cmd/frostfs-lens/internal/meta/inspect.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 
 	common "git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-lens/internal"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobovnicza"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/blobovniczatree"
 	meta "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/metabase"
 	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
@@ -40,7 +40,7 @@ func inspectFunc(cmd *cobra.Command, _ []string) {
 	common.ExitOnErr(cmd, common.Errf("could not check if the obj is small: %w", err))
 
 	if id := resStorageID.StorageID(); id != nil {
-		cmd.Printf("Object storageID: %s\n\n", blobovnicza.NewIDFromBytes(id).String())
+		cmd.Printf("Object storageID: %s\n\n", blobovniczatree.NewIDFromBytes(id).Path())
 	} else {
 		cmd.Printf("Object does not contain storageID\n\n")
 	}

cmd/frostfs-node/config.go

@@ -103,6 +103,7 @@ type applicationConfiguration struct {
 		shardPoolSize  uint32
 		shards         []shardCfg
 		lowMem         bool
+		rebuildWorkers uint32
 	}
 }
 
@@ -181,6 +182,8 @@ type subStorageCfg struct {
 	width           uint64
 	leafWidth       uint64
 	openedCacheSize int
+	initWorkerCount int
+	initInAdvance   bool
 }
 
 // readConfig fills applicationConfiguration with raw configuration values
@@ -212,6 +215,7 @@ func (a *applicationConfiguration) readConfig(c *config.Config) error {
 	a.EngineCfg.errorThreshold = engineconfig.ShardErrorThreshold(c)
 	a.EngineCfg.shardPoolSize = engineconfig.ShardPoolSize(c)
 	a.EngineCfg.lowMem = engineconfig.EngineLowMemoryConsumption(c)
+	a.EngineCfg.rebuildWorkers = engineconfig.EngineRebuildWorkersCount(c)
 
 	return engineconfig.IterateShards(c, false, func(sc *shardconfig.Config) error { return a.updateShardConfig(c, sc) })
 }
@@ -298,6 +302,8 @@ func (a *applicationConfiguration) setShardStorageConfig(newConfig *shardCfg, ol
 			sCfg.width = sub.ShallowWidth()
 			sCfg.leafWidth = sub.LeafWidth()
 			sCfg.openedCacheSize = sub.OpenedCacheSize()
+			sCfg.initWorkerCount = sub.InitWorkerCount()
+			sCfg.initInAdvance = sub.InitInAdvance()
 		case fstree.Type:
 			sub := fstreeconfig.From((*config.Config)(storagesCfg[i]))
 			sCfg.depth = sub.Depth()
@@ -701,13 +707,14 @@ func initCfgObject(appCfg *config.Config) cfgObject {
 }
 
 func (c *cfg) engineOpts() []engine.Option {
-	opts := make([]engine.Option, 0, 4)
+	var opts []engine.Option
 
 	opts = append(opts,
 		engine.WithShardPoolSize(c.EngineCfg.shardPoolSize),
 		engine.WithErrorThreshold(c.EngineCfg.errorThreshold),
 		engine.WithLogger(c.log),
 		engine.WithLowMemoryConsumption(c.EngineCfg.lowMem),
+		engine.WithRebuildWorkersCount(c.EngineCfg.rebuildWorkers),
 	)
 
 	if c.metricsCollector != nil {
@@ -796,7 +803,10 @@ func (c *cfg) getSubstorageOpts(shCfg shardCfg) []blobstor.SubStorage {
 				blobovniczatree.WithBlobovniczaShallowWidth(sRead.width),
 				blobovniczatree.WithBlobovniczaLeafWidth(sRead.leafWidth),
 				blobovniczatree.WithOpenedCacheSize(sRead.openedCacheSize),
+				blobovniczatree.WithInitWorkerCount(sRead.initWorkerCount),
+				blobovniczatree.WithInitInAdvance(sRead.initInAdvance),
 				blobovniczatree.WithLogger(c.log),
+				blobovniczatree.WithObjectSizeLimit(shCfg.smallSizeObjectLimit),
 			}
 
 			if c.metricsCollector != nil {

cmd/frostfs-node/config/engine/config.go

@@ -15,6 +15,9 @@ const (
 	// ShardPoolSizeDefault is a default value of routine pool size per-shard to
 	// process object PUT operations in a storage engine.
 	ShardPoolSizeDefault = 20
+	// RebuildWorkersCountDefault is a default value of the workers count to
+	// process storage rebuild operations in a storage engine.
+	RebuildWorkersCountDefault = 100
 )
 
 // ErrNoShardConfigured is returned when at least 1 shard is required but none are found.
@@ -88,3 +91,11 @@ func ShardErrorThreshold(c *config.Config) uint32 {
 func EngineLowMemoryConsumption(c *config.Config) bool {
 	return config.BoolSafe(c.Sub(subsection), "low_mem")
 }
+
+// EngineRebuildWorkersCount returns value of "rebuild_workers_count" config parmeter from "storage" section.
+func EngineRebuildWorkersCount(c *config.Config) uint32 {
+	if v := config.Uint32Safe(c.Sub(subsection), "rebuild_workers_count"); v > 0 {
+		return v
+	}
+	return RebuildWorkersCountDefault
+}

cmd/frostfs-node/config/engine/config_test.go

@@ -38,6 +38,7 @@ func TestEngineSection(t *testing.T) {
 		require.EqualValues(t, 0, engineconfig.ShardErrorThreshold(empty))
 		require.EqualValues(t, engineconfig.ShardPoolSizeDefault, engineconfig.ShardPoolSize(empty))
 		require.EqualValues(t, mode.ReadWrite, shardconfig.From(empty).Mode())
+		require.EqualValues(t, engineconfig.RebuildWorkersCountDefault, engineconfig.EngineRebuildWorkersCount(empty))
 	})
 
 	const path = "../../../../config/example/node"
@@ -47,6 +48,7 @@ func TestEngineSection(t *testing.T) {
 
 		require.EqualValues(t, 100, engineconfig.ShardErrorThreshold(c))
 		require.EqualValues(t, 15, engineconfig.ShardPoolSize(c))
+		require.EqualValues(t, uint32(1000), engineconfig.EngineRebuildWorkersCount(c))
 
 		err := engineconfig.IterateShards(c, true, func(sc *shardconfig.Config) error {
 			defer func() {
@@ -97,6 +99,8 @@ func TestEngineSection(t *testing.T) {
 				require.EqualValues(t, 4, blz.ShallowWidth())
 				require.EqualValues(t, 50, blz.OpenedCacheSize())
 				require.EqualValues(t, 10, blz.LeafWidth())
+				require.EqualValues(t, 10, blz.InitWorkerCount())
+				require.EqualValues(t, true, blz.InitInAdvance())
 
 				require.Equal(t, "tmp/0/blob", ss[1].Path())
 				require.EqualValues(t, 0o644, ss[1].Perm())
@@ -146,6 +150,7 @@ func TestEngineSection(t *testing.T) {
 				require.EqualValues(t, 4, blz.ShallowWidth())
 				require.EqualValues(t, 50, blz.OpenedCacheSize())
 				require.EqualValues(t, 10, blz.LeafWidth())
+				require.EqualValues(t, blobovniczaconfig.InitWorkerCountDefault, blz.InitWorkerCount())
 
 				require.Equal(t, "tmp/1/blob", ss[1].Path())
 				require.EqualValues(t, 0o644, ss[1].Perm())

cmd/frostfs-node/config/engine/shard/blobstor/blobovnicza/config.go

@@ -22,6 +22,9 @@ const (
 
 	// OpenedCacheSizeDefault is a default cache size of opened Blobovnicza's.
 	OpenedCacheSizeDefault = 16
+
+	// InitWorkerCountDefault is a default workers count to initialize Blobovnicza's.
+	InitWorkerCountDefault = 5
 )
 
 // From wraps config section into Config.
@@ -112,3 +115,29 @@ func (x *Config) LeafWidth() uint64 {
 		"leaf_width",
 	)
 }
+
+// InitWorkerCount returns the value of "init_worker_count" config parameter.
+//
+// Returns InitWorkerCountDefault if the value is not a positive number.
+func (x *Config) InitWorkerCount() int {
+	d := config.IntSafe(
+		(*config.Config)(x),
+		"init_worker_count",
+	)
+
+	if d > 0 {
+		return int(d)
+	}
+
+	return InitWorkerCountDefault
+}
+
+// InitInAdvance returns the value of "init_in_advance" config parameter.
+//
+// Returns False if the value is not defined or invalid.
+func (x *Config) InitInAdvance() bool {
+	return config.BoolSafe(
+		(*config.Config)(x),
+		"init_in_advance",
+	)
+}

config/example/node.env

@@ -92,6 +92,7 @@ FROSTFS_OBJECT_DELETE_TOMBSTONE_LIFETIME=10
 # Storage engine section
 FROSTFS_STORAGE_SHARD_POOL_SIZE=15
 FROSTFS_STORAGE_SHARD_RO_ERROR_THRESHOLD=100
+FROSTFS_STORAGE_REBUILD_WORKERS_COUNT=1000
 ## 0 shard
 ### Flag to refill Metabase from BlobStor
 FROSTFS_STORAGE_SHARD_0_RESYNC_METABASE=false
@@ -125,6 +126,8 @@ FROSTFS_STORAGE_SHARD_0_BLOBSTOR_0_DEPTH=1
 FROSTFS_STORAGE_SHARD_0_BLOBSTOR_0_WIDTH=4
 FROSTFS_STORAGE_SHARD_0_BLOBSTOR_0_OPENED_CACHE_CAPACITY=50
 FROSTFS_STORAGE_SHARD_0_BLOBSTOR_0_LEAF_WIDTH=10
+FROSTFS_STORAGE_SHARD_0_BLOBSTOR_0_INIT_WORKER_COUNT=10
+FROSTFS_STORAGE_SHARD_0_BLOBSTOR_0_INIT_IN_ADVANCE=TRUE
 ### FSTree config
 FROSTFS_STORAGE_SHARD_0_BLOBSTOR_1_TYPE=fstree
 FROSTFS_STORAGE_SHARD_0_BLOBSTOR_1_PATH=tmp/0/blob

config/example/node.json

@@ -137,6 +137,7 @@
   "storage": {
     "shard_pool_size": 15,
     "shard_ro_error_threshold": 100,
+    "rebuild_workers_count": 1000,
     "shard": {
       "0": {
         "mode": "read-only",
@@ -172,7 +173,9 @@
             "depth": 1,
             "width": 4,
             "opened_cache_capacity": 50,
-            "leaf_width": 10
+            "leaf_width": 10,
+            "init_worker_count": 10,
+            "init_in_advance": true
           },
           {
             "type": "fstree",

config/example/node.yaml

@@ -116,6 +116,7 @@ storage:
   # note: shard configuration can be omitted for relay node (see `node.relay`)
   shard_pool_size: 15 # size of per-shard worker pools used for PUT operations
   shard_ro_error_threshold: 100 # amount of errors to occur before shard is made read-only (default: 0, ignore errors)
+  rebuild_workers_count: 1000 # count of rebuild storage concurrent workers
 
   shard:
     default: # section with the default shard parameters
@@ -184,6 +185,8 @@ storage:
       blobstor:
         - type: blobovnicza
           path: tmp/0/blob/blobovnicza
+          init_worker_count: 10 #count of workers to initialize blobovniczas
+          init_in_advance: true
         - type: fstree
           path: tmp/0/blob  # blobstor path
 

internal/logs/logs.go

@@ -519,4 +519,36 @@ const (
 	FailedToCountWritecacheItems                                            = "failed to count writecache items"
 	AttemtToCloseAlreadyClosedBlobovnicza                                   = "attempt to close an already closed blobovnicza"
 	FailedToGetContainerCounters                                            = "failed to get container counters values"
+	FailedToRebuildBlobstore                                                = "failed to rebuild blobstore"
+	BlobstoreRebuildStarted                                                 = "blobstore rebuild started"
+	BlobstoreRebuildCompletedSuccessfully                                   = "blobstore rebuild completed successfully"
+	BlobstoreRebuildStopped                                                 = "blobstore rebuild stopped"
+	BlobovniczaTreeFixingFileExtensions                                     = "fixing blobovnicza tree file extensions..."
+	BlobovniczaTreeFixingFileExtensionsCompletedSuccessfully                = "fixing blobovnicza tree file extensions completed successfully"
+	BlobovniczaTreeFixingFileExtensionsFailed                               = "failed to fix blobovnicza tree file extensions"
+	BlobovniczaTreeFixingFileExtensionForFile                               = "fixing blobovnicza file extension..."
+	BlobovniczaTreeFixingFileExtensionCompletedSuccessfully                 = "fixing blobovnicza file extension completed successfully"
+	BlobovniczaTreeFixingFileExtensionFailed                                = "failed to fix blobovnicza file extension"
+	BlobstorRebuildFailedToRebuildStorages                                  = "failed to rebuild storages"
+	BlobstorRebuildRebuildStoragesCompleted                                 = "storages rebuild completed"
+	BlobovniczaTreeCollectingDBToRebuild                                    = "collecting blobovniczas to rebuild..."
+	BlobovniczaTreeCollectingDBToRebuildFailed                              = "collecting blobovniczas to rebuild failed"
+	BlobovniczaTreeCollectingDBToRebuildSuccess                             = "collecting blobovniczas to rebuild completed successfully"
+	BlobovniczaTreeRebuildingBlobovnicza                                    = "rebuilding blobovnicza..."
+	BlobovniczaTreeRebuildingBlobovniczaFailed                              = "rebuilding blobovnicza failed"
+	BlobovniczaTreeRebuildingBlobovniczaSuccess                             = "rebuilding blobovnicza completed successfully"
+	BlobovniczatreeCouldNotPutMoveInfoToSourceBlobovnicza                   = "could not put move info to source blobovnicza"
+	BlobovniczatreeCouldNotUpdateStorageID                                  = "could not update storage ID"
+	BlobovniczatreeCouldNotDropMoveInfo                                     = "could not drop move info from source blobovnicza"
+	BlobovniczatreeCouldNotDeleteFromSource                                 = "could not delete object from source blobovnicza"
+	BlobovniczaTreeCompletingPreviousRebuild                                = "completing previous rebuild if failed..."
+	BlobovniczaTreeCompletedPreviousRebuildSuccess                          = "previous rebuild completed successfully"
+	BlobovniczaTreeCompletedPreviousRebuildFailed                           = "failed to complete previous rebuild"
+	BlobovniczatreeCouldNotCheckExistenceInSourceDB                         = "could not check object existence in source blobovnicza"
+	BlobovniczatreeCouldNotCheckExistenceInTargetDB                         = "could not check object existence in target blobovnicza"
+	BlobovniczatreeCouldNotGetObjectFromSourceDB                            = "could not get object from source blobovnicza"
+	BlobovniczatreeCouldNotPutObjectToTargetDB                              = "could not put object to target blobovnicza"
+	BlobovniczaSavingCountersToMeta                                         = "saving counters to blobovnicza's meta..."
+	BlobovniczaSavingCountersToMetaSuccess                                  = "saving counters to blobovnicza's meta completed successfully"
+	BlobovniczaSavingCountersToMetaFailed                                   = "saving counters to blobovnicza's meta failed"
 )

pkg/local_object_storage/blobovnicza/control.go

@@ -104,17 +104,42 @@ func (b *Blobovnicza) Init() error {
 func (b *Blobovnicza) initializeCounters() error {
 	var size uint64
 	var items uint64
+	var sizeExists bool
+	var itemsCountExists bool
+
 	err := b.boltDB.View(func(tx *bbolt.Tx) error {
-		return b.iterateAllBuckets(tx, func(lower, upper uint64, b *bbolt.Bucket) (bool, error) {
+		size, sizeExists = hasDataSize(tx)
-			keysN := uint64(b.Stats().KeyN)
+		items, itemsCountExists = hasItemsCount(tx)
-			size += keysN * upper
+
-			items += keysN
+		if sizeExists && itemsCountExists {
-			return false, nil
+			return nil
+		}
+
+		return b.iterateAllDataBuckets(tx, func(lower, upper uint64, b *bbolt.Bucket) (bool, error) {
+			return false, b.ForEach(func(k, v []byte) error {
+				size += uint64(len(k) + len(v))
+				items++
+				return nil
+			})
 		})
 	})
 	if err != nil {
 		return fmt.Errorf("can't determine DB size: %w", err)
 	}
+	if (!sizeExists || !itemsCountExists) && !b.boltOptions.ReadOnly {
+		b.log.Debug(logs.BlobovniczaSavingCountersToMeta, zap.Uint64("size", size), zap.Uint64("items", items))
+		if err := b.boltDB.Update(func(tx *bbolt.Tx) error {
+			if err := saveDataSize(tx, size); err != nil {
+				return err
+			}
+			return saveItemsCount(tx, items)
+		}); err != nil {
+			b.log.Debug(logs.BlobovniczaSavingCountersToMetaFailed, zap.Uint64("size", size), zap.Uint64("items", items))
+			return fmt.Errorf("can't save blobovnicza's size and items count: %w", err)
+		}
+		b.log.Debug(logs.BlobovniczaSavingCountersToMetaSuccess, zap.Uint64("size", size), zap.Uint64("items", items))
+	}
+
 	b.dataSize.Store(size)
 	b.itemsCount.Store(items)
 	b.metrics.AddOpenBlobovniczaSize(size)

pkg/local_object_storage/blobovnicza/delete.go

@@ -49,9 +49,10 @@ func (b *Blobovnicza) Delete(ctx context.Context, prm DeletePrm) (DeleteRes, err
 	var sizeUpperBound uint64
 	var sizeLowerBound uint64
 	var dataSize uint64
+	var recordSize uint64
 
 	err := b.boltDB.Update(func(tx *bbolt.Tx) error {
-		return b.iterateAllBuckets(tx, func(lower, upper uint64, buck *bbolt.Bucket) (bool, error) {
+		err := b.iterateAllDataBuckets(tx, func(lower, upper uint64, buck *bbolt.Bucket) (bool, error) {
 			objData := buck.Get(addrKey)
 			if objData == nil {
 				// object is not in bucket => continue iterating
@@ -60,9 +61,27 @@ func (b *Blobovnicza) Delete(ctx context.Context, prm DeletePrm) (DeleteRes, err
 			dataSize = uint64(len(objData))
 			sizeLowerBound = lower
 			sizeUpperBound = upper
+			recordSize = dataSize + uint64(len(addrKey))
 			found = true
 			return true, buck.Delete(addrKey)
 		})
+		if err != nil {
+			return err
+		}
+		if found {
+			return updateMeta(tx, func(count, size uint64) (uint64, uint64) {
+				if count > 0 {
+					count--
+				}
+				if size >= recordSize {
+					size -= recordSize
+				} else {
+					size = 0
+				}
+				return count, size
+			})
+		}
+		return nil
 	})
 
 	if err == nil && !found {
@@ -75,7 +94,7 @@ func (b *Blobovnicza) Delete(ctx context.Context, prm DeletePrm) (DeleteRes, err
 			zap.String("range", stringifyBounds(sizeLowerBound, sizeUpperBound)),
 			zap.String("trace_id", tracingPkg.GetTraceID(ctx)),
 		)
-		b.itemDeleted(sizeUpperBound)
+		b.itemDeleted(recordSize)
 	}
 
 	return DeleteRes{}, err

pkg/local_object_storage/blobovnicza/exists.go

@@ -24,7 +24,10 @@ func (b *Blobovnicza) Exists(ctx context.Context, addr oid.Address) (bool, error
 	addrKey := addressKey(addr)
 
 	err := b.boltDB.View(func(tx *bbolt.Tx) error {
-		return tx.ForEach(func(_ []byte, buck *bbolt.Bucket) error {
+		return tx.ForEach(func(bucketName []byte, buck *bbolt.Bucket) error {
+			if isNonDataBucket(bucketName) {
+				return nil
+			}
 			exists = buck.Get(addrKey) != nil
 			if exists {
 				return errInterruptForEach

pkg/local_object_storage/blobovnicza/get.go

@@ -57,7 +57,11 @@ func (b *Blobovnicza) Get(ctx context.Context, prm GetPrm) (GetRes, error) {
 	)
 
 	if err := b.boltDB.View(func(tx *bbolt.Tx) error {
-		return tx.ForEach(func(_ []byte, buck *bbolt.Bucket) error {
+		return tx.ForEach(func(bucketName []byte, buck *bbolt.Bucket) error {
+			if isNonDataBucket(bucketName) {
+				return nil
+			}
+
 			data = buck.Get(addrKey)
 			if data == nil {
 				return nil

pkg/local_object_storage/blobovnicza/iterate.go

@@ -12,11 +12,11 @@ import (
 	"go.opentelemetry.io/otel/trace"
 )
 
-// iterateAllBuckets iterates all buckets in db
+// iterateAllDataBuckets iterates all buckets in db
 //
 // If the maximum size of the object (b.objSizeLimit) has been changed to lower value,
 // then there may be more buckets than the current limit of the object size.
-func (b *Blobovnicza) iterateAllBuckets(tx *bbolt.Tx, f func(uint64, uint64, *bbolt.Bucket) (bool, error)) error {
+func (b *Blobovnicza) iterateAllDataBuckets(tx *bbolt.Tx, f func(uint64, uint64, *bbolt.Bucket) (bool, error)) error {
 	return b.iterateBucketKeys(false, func(lower uint64, upper uint64, key []byte) (bool, error) {
 		buck := tx.Bucket(key)
 		if buck == nil {
@@ -138,7 +138,10 @@ func (b *Blobovnicza) Iterate(ctx context.Context, prm IteratePrm) (IterateRes,
 	var elem IterationElement
 
 	if err := b.boltDB.View(func(tx *bbolt.Tx) error {
-		return tx.ForEach(func(name []byte, buck *bbolt.Bucket) error {
+		return tx.ForEach(func(bucketName []byte, buck *bbolt.Bucket) error {
+			if isNonDataBucket(bucketName) {
+				return nil
+			}
 			return buck.ForEach(func(k, v []byte) error {
 				select {
 				case <-ctx.Done():

pkg/local_object_storage/blobovnicza/meta.go

@@ -0,0 +1,103 @@
+package blobovnicza
+
+import (
+	"bytes"
+	"encoding/binary"
+
+	"go.etcd.io/bbolt"
+)
+
+const (
+	dataSizeAndItemsCountBufLength = 8
+)
+
+var (
+	metaBucketName = []byte("META")
+	dataSizeKey    = []byte("data_size")
+	itemsCountKey  = []byte("items_count")
+)
+
+func isNonDataBucket(bucketName []byte) bool {
+	return bytes.Equal(bucketName, incompletedMoveBucketName) || bytes.Equal(bucketName, metaBucketName)
+}
+
+func hasDataSize(tx *bbolt.Tx) (uint64, bool) {
+	b := tx.Bucket(metaBucketName)
+	if b == nil {
+		return 0, false
+	}
+	v := b.Get(dataSizeKey)
+	if v == nil {
+		return 0, false
+	}
+	if len(v) != dataSizeAndItemsCountBufLength {
+		return 0, false
+	}
+	return binary.LittleEndian.Uint64(v), true
+}
+
+func hasItemsCount(tx *bbolt.Tx) (uint64, bool) {
+	b := tx.Bucket(metaBucketName)
+	if b == nil {
+		return 0, false
+	}
+	v := b.Get(itemsCountKey)
+	if v == nil {
+		return 0, false
+	}
+	if len(v) != dataSizeAndItemsCountBufLength {
+		return 0, false
+	}
+	return binary.LittleEndian.Uint64(v), true
+}
+
+func saveDataSize(tx *bbolt.Tx, size uint64) error {
+	b, err := tx.CreateBucketIfNotExists(metaBucketName)
+	if err != nil {
+		return err
+	}
+	buf := make([]byte, dataSizeAndItemsCountBufLength)
+	binary.LittleEndian.PutUint64(buf, size)
+	return b.Put(dataSizeKey, buf)
+}
+
+func saveItemsCount(tx *bbolt.Tx, count uint64) error {
+	b, err := tx.CreateBucketIfNotExists(metaBucketName)
+	if err != nil {
+		return err
+	}
+	buf := make([]byte, dataSizeAndItemsCountBufLength)
+	binary.LittleEndian.PutUint64(buf, count)
+	return b.Put(itemsCountKey, buf)
+}
+
+func updateMeta(tx *bbolt.Tx, updateValues func(count, size uint64) (uint64, uint64)) error {
+	b, err := tx.CreateBucketIfNotExists(metaBucketName)
+	if err != nil {
+		return err
+	}
+
+	var count uint64
+	var size uint64
+
+	v := b.Get(itemsCountKey)
+	if v != nil {
+		count = binary.LittleEndian.Uint64(v)
+	}
+
+	v = b.Get(dataSizeKey)
+	if v != nil {
+		size = binary.LittleEndian.Uint64(v)
+	}
+
+	count, size = updateValues(count, size)
+
+	buf := make([]byte, dataSizeAndItemsCountBufLength)
+	binary.LittleEndian.PutUint64(buf, size)
+	if err := b.Put(dataSizeKey, buf); err != nil {
+		return err
+	}
+
+	binary.LittleEndian.PutUint64(buf, count)
+	return b.Put(itemsCountKey, buf)
+}

pkg/local_object_storage/blobovnicza/move.go

@@ -0,0 +1,108 @@
+package blobovnicza
+
+import (
+	"context"
+	"fmt"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"go.etcd.io/bbolt"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+)
+
+var incompletedMoveBucketName = []byte("INCOMPLETED_MOVE")
+
+type MoveInfo struct {
+	Address         oid.Address
+	TargetStorageID []byte
+}
+
+func (b *Blobovnicza) PutMoveInfo(ctx context.Context, prm MoveInfo) error {
+	_, span := tracing.StartSpanFromContext(ctx, "Blobovnicza.PutMoveInfo",
+		trace.WithAttributes(
+			attribute.String("path", b.path),
+			attribute.String("address", prm.Address.EncodeToString()),
+			attribute.String("target_storage_id", string(prm.TargetStorageID)),
+		))
+	defer span.End()
+
+	key := addressKey(prm.Address)
+
+	return b.boltDB.Update(func(tx *bbolt.Tx) error {
+		bucket, err := tx.CreateBucketIfNotExists(incompletedMoveBucketName)
+		if err != nil {
+			return err
+		}
+
+		if err := bucket.Put(key, prm.TargetStorageID); err != nil {
+			return fmt.Errorf("(%T) failed to save move info: %w", b, err)
+		}
+
+		return nil
+	})
+}
+
+func (b *Blobovnicza) DropMoveInfo(ctx context.Context, address oid.Address) error {
+	_, span := tracing.StartSpanFromContext(ctx, "Blobovnicza.DropMoveInfo",
+		trace.WithAttributes(
+			attribute.String("path", b.path),
+			attribute.String("address", address.EncodeToString()),
+		))
+	defer span.End()
+
+	key := addressKey(address)
+
+	return b.boltDB.Update(func(tx *bbolt.Tx) error {
+		bucket := tx.Bucket(incompletedMoveBucketName)
+		if bucket == nil {
+			return nil
+		}
+
+		if err := bucket.Delete(key); err != nil {
+			return fmt.Errorf("(%T) failed to drop move info: %w", b, err)
+		}
+
+		c := bucket.Cursor()
+		k, v := c.First()
+		bucketEmpty := k == nil && v == nil
+		if bucketEmpty {
+			return tx.DeleteBucket(incompletedMoveBucketName)
+		}
+
+		return nil
+	})
+}
+
+func (b *Blobovnicza) ListMoveInfo(ctx context.Context) ([]MoveInfo, error) {
+	_, span := tracing.StartSpanFromContext(ctx, "Blobovnicza.ListMoveInfo",
+		trace.WithAttributes(
+			attribute.String("path", b.path),
+		))
+	defer span.End()
+
+	var result []MoveInfo
+	if err := b.boltDB.View(func(tx *bbolt.Tx) error {
+		bucket := tx.Bucket(incompletedMoveBucketName)
+		if bucket == nil {
+			return nil
+		}
+		return bucket.ForEach(func(k, v []byte) error {
+			var addr oid.Address
+			storageID := make([]byte, len(v))
+			if err := addressFromKey(&addr, k); err != nil {
+				return err
+			}
+			copy(storageID, v)
+			result = append(result, MoveInfo{
+				Address:         addr,
+				TargetStorageID: storageID,
+			})
+			return nil
+		})
+	}); err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}

pkg/local_object_storage/blobovnicza/put.go

@@ -56,8 +56,9 @@ func (b *Blobovnicza) Put(ctx context.Context, prm PutPrm) (PutRes, error) {
 	defer span.End()
 
 	sz := uint64(len(prm.objData))
-	bucketName, upperBound := bucketForSize(sz)
+	bucketName := bucketForSize(sz)
 	key := addressKey(prm.addr)
+	recordSize := sz + uint64(len(key))
 
 	err := b.boltDB.Batch(func(tx *bbolt.Tx) error {
 		buck := tx.Bucket(bucketName)
@@ -73,10 +74,12 @@ func (b *Blobovnicza) Put(ctx context.Context, prm PutPrm) (PutRes, error) {
 			return fmt.Errorf("(%T) could not save object in bucket: %w", b, err)
 		}
 
-		return nil
+		return updateMeta(tx, func(count, size uint64) (uint64, uint64) {
+			return count + 1, size + recordSize
+		})
 	})
 	if err == nil {
-		b.itemAdded(upperBound)
+		b.itemAdded(recordSize)
 	}
 
 	return PutRes{}, err

pkg/local_object_storage/blobovnicza/sizes.go

@@ -29,9 +29,8 @@ func bucketKeyFromBounds(upperBound uint64) []byte {
 	return buf[:ln]
 }
 
-func bucketForSize(sz uint64) ([]byte, uint64) {
+func bucketForSize(sz uint64) []byte {
-	upperBound := upperPowerOfTwo(sz)
+	return bucketKeyFromBounds(upperPowerOfTwo(sz))
-	return bucketKeyFromBounds(upperBound), upperBound
 }
 
 func upperPowerOfTwo(v uint64) uint64 {

pkg/local_object_storage/blobovnicza/sizes_test.go

@@ -34,7 +34,7 @@ func TestSizes(t *testing.T) {
 			upperBound: 4 * firstBucketBound,
 		},
 	} {
-		key, _ := bucketForSize(item.sz)
+		key := bucketForSize(item.sz)
 		require.Equal(t, bucketKeyFromBounds(item.upperBound), key)
 	}
 }

pkg/local_object_storage/blobstor/blobovniczatree/active.go

@@ -21,8 +21,8 @@ func (db *activeDB) Close() {
 	db.shDB.Close()
 }
 
-func (db *activeDB) Path() string {
+func (db *activeDB) SystemPath() string {
-	return db.shDB.Path()
+	return db.shDB.SystemPath()
 }
 
 // activeDBManager manages active blobovnicza instances (that is, those that are being used for Put).
@@ -154,7 +154,7 @@ func (m *activeDBManager) getNextSharedDB(lvlPath string) (*sharedDB, error) {
 	var next *sharedDB
 
 	for iterCount < m.leafWidth {
-		path := filepath.Join(lvlPath, u64ToHexString(idx))
+		path := filepath.Join(lvlPath, u64ToHexStringExt(idx))
 		shDB := m.dbManager.GetByPath(path)
 		db, err := shDB.Open() // open db to hold active DB open, will be closed if db is full, after m.replace or by activeDBManager.Close()
 		if err != nil {
@@ -192,7 +192,7 @@ func (m *activeDBManager) hasActiveDB(lvlPath string) (bool, uint64) {
 	if !ok {
 		return false, 0
 	}
-	return true, u64FromHexString(filepath.Base(db.Path()))
+	return true, u64FromHexString(filepath.Base(db.SystemPath()))
 }
 
 func (m *activeDBManager) replace(lvlPath string, shDB *sharedDB) (*sharedDB, bool) {

pkg/local_object_storage/blobstor/blobovniczatree/blobovnicza.go

@@ -4,6 +4,8 @@ import (
 	"errors"
 	"fmt"
 	"strconv"
+	"strings"
+	"sync"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/compression"
@@ -54,15 +56,22 @@ import (
 type Blobovniczas struct {
 	cfg
 
-	commondbManager *dbManager
+	commondbManager        *dbManager
-	activeDBManager *activeDBManager
+	activeDBManager        *activeDBManager
-	dbCache         *dbCache
+	dbCache                *dbCache
+	deleteProtectedObjects *addressMap
+	dbFilesGuard           *sync.RWMutex
+	rebuildGuard           *sync.RWMutex
 }
 
 var _ common.Storage = (*Blobovniczas)(nil)
 
 var errPutFailed = errors.New("could not save the object in any blobovnicza")
 
+const (
+	dbExtension = ".db"
+)
+
 // NewBlobovniczaTree returns new instance of blobovniczas tree.
 func NewBlobovniczaTree(opts ...Option) (blz *Blobovniczas) {
 	blz = new(Blobovniczas)
@@ -76,9 +85,12 @@ func NewBlobovniczaTree(opts ...Option) (blz *Blobovniczas) {
 		blz.blzLeafWidth = blz.blzShallowWidth
 	}
 
-	blz.commondbManager = newDBManager(blz.rootPath, blz.blzOpts, blz.blzLeafWidth, blz.readOnly, blz.metrics.Blobovnicza(), blz.log)
+	blz.commondbManager = newDBManager(blz.rootPath, blz.blzOpts, blz.readOnly, blz.metrics.Blobovnicza(), blz.log)
 	blz.activeDBManager = newActiveDBManager(blz.commondbManager, blz.blzLeafWidth)
 	blz.dbCache = newDBCache(blz.openedCacheSize, blz.commondbManager)
+	blz.deleteProtectedObjects = newAddressMap()
+	blz.dbFilesGuard = &sync.RWMutex{}
+	blz.rebuildGuard = &sync.RWMutex{}
 
 	return blz
 }
@@ -94,14 +106,16 @@ func addressHash(addr *oid.Address, path string) uint64 {
 	return hrw.StringHash(a + path)
 }
 
-// converts uint64 to hex string.
 func u64ToHexString(ind uint64) string {
 	return strconv.FormatUint(ind, 16)
 }
 
-// converts uint64 hex string to uint64.
+func u64ToHexStringExt(ind uint64) string {
+	return strconv.FormatUint(ind, 16) + dbExtension
+}
+
 func u64FromHexString(str string) uint64 {
-	v, err := strconv.ParseUint(str, 16, 64)
+	v, err := strconv.ParseUint(strings.TrimSuffix(str, dbExtension), 16, 64)
 	if err != nil {
 		panic(fmt.Sprintf("blobovnicza name is not an index %s", str))
 	}

pkg/local_object_storage/blobstor/blobovniczatree/cache.go

@@ -15,8 +15,9 @@ import (
 type dbCache struct {
 	cacheGuard *sync.RWMutex
 	cache      simplelru.LRUCache[string, *sharedDB]
-	pathLock   *utilSync.KeyLocker[string]
+	pathLock   *utilSync.KeyLocker[string] // the order of locks is important: pathLock first, cacheGuard second
 	closed     bool
+	nonCached  map[string]struct{}
 
 	dbManager *dbManager
 }
@@ -34,6 +35,7 @@ func newDBCache(size int, dbManager *dbManager) *dbCache {
 		cache:      cache,
 		dbManager:  dbManager,
 		pathLock:   utilSync.NewKeyLocker[string](),
+		nonCached:  make(map[string]struct{}),
 	}
 }
 
@@ -59,6 +61,27 @@ func (c *dbCache) GetOrCreate(path string) *sharedDB {
 	return c.create(path)
 }
 
+func (c *dbCache) EvictAndMarkNonCached(path string) {
+	c.pathLock.Lock(path)
+	defer c.pathLock.Unlock(path)
+
+	c.cacheGuard.Lock()
+	defer c.cacheGuard.Unlock()
+
+	c.cache.Remove(path)
+	c.nonCached[path] = struct{}{}
+}
+
+func (c *dbCache) RemoveFromNonCached(path string) {
+	c.pathLock.Lock(path)
+	defer c.pathLock.Unlock(path)
+
+	c.cacheGuard.Lock()
+	defer c.cacheGuard.Unlock()
+
+	delete(c.nonCached, path)
+}
+
 func (c *dbCache) getExisted(path string) *sharedDB {
 	c.cacheGuard.Lock()
 	defer c.cacheGuard.Unlock()
@@ -94,7 +117,9 @@ func (c *dbCache) put(path string, db *sharedDB) bool {
 	c.cacheGuard.Lock()
 	defer c.cacheGuard.Unlock()
 
-	if !c.closed {
+	_, isNonCached := c.nonCached[path]
+
+	if !isNonCached && !c.closed {
 		c.cache.Add(path, db)
 		return true
 	}

pkg/local_object_storage/blobstor/blobovniczatree/control.go

@@ -2,15 +2,24 @@ package blobovniczatree
 
 import (
 	"context"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util"
 	"go.uber.org/zap"
+	"golang.org/x/sync/errgroup"
 )
 
+var errFailedToChangeExtensionReadOnly = errors.New("failed to change blobovnicza extension: read only mode")
+
 // Open opens blobovnicza tree.
 func (b *Blobovniczas) Open(readOnly bool) error {
 	b.readOnly = readOnly
 	b.metrics.SetMode(readOnly)
+	b.metrics.SetRebuildStatus(rebuildStatusNotStarted)
 	b.openManagers()
 	return nil
 }
@@ -21,22 +30,84 @@ func (b *Blobovniczas) Open(readOnly bool) error {
 func (b *Blobovniczas) Init() error {
 	b.log.Debug(logs.BlobovniczatreeInitializingBlobovniczas)
 
+	b.log.Debug(logs.BlobovniczaTreeFixingFileExtensions)
+	if err := b.addDBExtensionToDBs(b.rootPath, 0); err != nil {
+		b.log.Error(logs.BlobovniczaTreeFixingFileExtensionsFailed, zap.Error(err))
+		return err
+	}
+	b.log.Debug(logs.BlobovniczaTreeFixingFileExtensionsCompletedSuccessfully)
+
 	if b.readOnly {
 		b.log.Debug(logs.BlobovniczatreeReadonlyModeSkipBlobovniczasInitialization)
 		return nil
 	}
 
-	return b.iterateLeaves(context.TODO(), func(p string) (bool, error) {
+	return b.initializeDBs(context.TODO())
-		shBlz := b.getBlobovniczaWithoutCaching(p)
+}
-		_, err := shBlz.Open()
-		if err != nil {
-			return true, err
-		}
-		defer shBlz.Close()
 
-		b.log.Debug(logs.BlobovniczatreeBlobovniczaSuccessfullyInitializedClosing, zap.String("id", p))
+func (b *Blobovniczas) initializeDBs(ctx context.Context) error {
+	err := util.MkdirAllX(b.rootPath, b.perm)
+	if err != nil {
+		return err
+	}
+
+	eg, egCtx := errgroup.WithContext(ctx)
+	eg.SetLimit(b.blzInitWorkerCount)
+	visited := make(map[string]struct{})
+	err = b.iterateExistingDBPaths(egCtx, func(p string) (bool, error) {
+		visited[p] = struct{}{}
+		eg.Go(func() error {
+			shBlz := b.getBlobovniczaWithoutCaching(p)
+			blz, err := shBlz.Open()
+			if err != nil {
+				return err
+			}
+			defer shBlz.Close()
+
+			moveInfo, err := blz.ListMoveInfo(egCtx)
+			if err != nil {
+				return err
+			}
+			for _, move := range moveInfo {
+				b.deleteProtectedObjects.Add(move.Address)
+			}
+
+			b.log.Debug(logs.BlobovniczatreeBlobovniczaSuccessfullyInitializedClosing, zap.String("id", p))
+			return nil
+		})
 		return false, nil
 	})
+	if err != nil {
+		_ = eg.Wait()
+		return err
+	}
+
+	if b.createDBInAdvance {
+		err = b.iterateSortedLeaves(egCtx, nil, func(p string) (bool, error) {
+			if _, found := visited[p]; found {
+				return false, nil
+			}
+			eg.Go(func() error {
+				shBlz := b.getBlobovniczaWithoutCaching(p)
+				_, err := shBlz.Open()
+				if err != nil {
+					return err
+				}
+				defer shBlz.Close()
+
+				b.log.Debug(logs.BlobovniczatreeBlobovniczaSuccessfullyInitializedClosing, zap.String("id", p))
+				return nil
+			})
+			return false, nil
+		})
+
+		if err != nil {
+			_ = eg.Wait()
+			return err
+		}
+	}
+
+	return eg.Wait()
 }
 
 func (b *Blobovniczas) openManagers() {
@@ -64,3 +135,37 @@ func (b *Blobovniczas) getBlobovnicza(p string) *sharedDB {
 func (b *Blobovniczas) getBlobovniczaWithoutCaching(p string) *sharedDB {
 	return b.commondbManager.GetByPath(p)
 }
+
+func (b *Blobovniczas) addDBExtensionToDBs(path string, depth uint64) error {
+	entries, err := os.ReadDir(path)
+	if os.IsNotExist(err) && depth == 0 {
+		return nil
+	}
+
+	for _, entry := range entries {
+		if entry.IsDir() {
+			if err := b.addDBExtensionToDBs(filepath.Join(path, entry.Name()), depth+1); err != nil {
+				return err
+			}
+			continue
+		}
+
+		if strings.HasSuffix(entry.Name(), dbExtension) {
+			continue
+		}
+		if b.readOnly {
+			return errFailedToChangeExtensionReadOnly
+		}
+
+		sourcePath := filepath.Join(path, entry.Name())
+		targetPath := filepath.Join(path, entry.Name()+dbExtension)
+		b.log.Debug(logs.BlobovniczaTreeFixingFileExtensionForFile, zap.String("source", sourcePath), zap.String("target", targetPath))
+		if err := os.Rename(sourcePath, targetPath); err != nil {
+			b.log.Error(logs.BlobovniczaTreeFixingFileExtensionFailed, zap.String("source", sourcePath), zap.String("target", targetPath), zap.Error(err))
+			return err
+		}
+		b.log.Debug(logs.BlobovniczaTreeFixingFileExtensionCompletedSuccessfully, zap.String("source", sourcePath), zap.String("target", targetPath))
+	}
+
+	return nil
+}

pkg/local_object_storage/blobstor/blobovniczatree/control_test.go

@@ -0,0 +1,189 @@
+package blobovniczatree
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	objectCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobovnicza"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/internal/blobstortest"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDBExtensionFix(t *testing.T) {
+	root := t.TempDir()
+	createTestTree(t, 0, 2, 3, root)
+	t.Run("adds suffix if not exists", func(t *testing.T) {
+		openAndCloseTestTree(t, 2, 3, root)
+		validateTestTree(t, root)
+	})
+
+	t.Run("not adds second suffix if exists", func(t *testing.T) {
+		openAndCloseTestTree(t, 2, 3, root)
+		validateTestTree(t, root)
+	})
+}
+
+func createTestTree(t *testing.T, currentDepth, depth, width uint64, path string) {
+	if currentDepth == depth {
+		var w uint64
+		for ; w < width; w++ {
+			dbPath := filepath.Join(path, u64ToHexString(w))
+			b := blobovnicza.New(blobovnicza.WithPath(dbPath))
+			require.NoError(t, b.Open())
+			require.NoError(t, b.Init())
+			require.NoError(t, b.Close())
+		}
+		return
+	}
+
+	var w uint64
+	for ; w < width; w++ {
+		createTestTree(t, currentDepth+1, depth, width, filepath.Join(path, u64ToHexString(w)))
+	}
+}
+
+func openAndCloseTestTree(t *testing.T, depth, width uint64, path string) {
+	blz := NewBlobovniczaTree(
+		WithBlobovniczaShallowDepth(depth),
+		WithBlobovniczaShallowWidth(width),
+		WithRootPath(path),
+	)
+	require.NoError(t, blz.Open(false))
+	require.NoError(t, blz.Init())
+	require.NoError(t, blz.Close())
+}
+
+func validateTestTree(t *testing.T, path string) {
+	entries, err := os.ReadDir(path)
+	require.NoError(t, err)
+
+	for _, entry := range entries {
+		if entry.IsDir() {
+			validateTestTree(t, filepath.Join(path, entry.Name()))
+		} else {
+			require.True(t, strings.HasSuffix(entry.Name(), dbExtension))
+			require.False(t, strings.HasSuffix(strings.TrimSuffix(entry.Name(), dbExtension), dbExtension))
+		}
+	}
+}
+
+func TestObjectsAvailableAfterDepthAndWidthEdit(t *testing.T) {
+	t.Parallel()
+
+	rootDir := t.TempDir()
+
+	blz := NewBlobovniczaTree(
+		WithBlobovniczaShallowDepth(3),
+		WithBlobovniczaShallowWidth(5),
+		WithRootPath(rootDir),
+	)
+
+	require.NoError(t, blz.Open(false))
+	require.NoError(t, blz.Init())
+
+	obj35 := blobstortest.NewObject(10 * 1024)
+	addr35 := objectCore.AddressOf(obj35)
+	raw, err := obj35.Marshal()
+	require.NoError(t, err)
+
+	pRes35, err := blz.Put(context.Background(), common.PutPrm{
+		Address: addr35,
+		Object:  obj35,
+		RawData: raw,
+	})
+	require.NoError(t, err)
+
+	gRes, err := blz.Get(context.Background(), common.GetPrm{
+		Address:   addr35,
+		StorageID: pRes35.StorageID,
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, obj35, gRes.Object)
+
+	gRes, err = blz.Get(context.Background(), common.GetPrm{
+		Address: addr35,
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, obj35, gRes.Object)
+
+	require.NoError(t, blz.Close())
+
+	// change depth and width
+	blz = NewBlobovniczaTree(
+		WithBlobovniczaShallowDepth(5),
+		WithBlobovniczaShallowWidth(2),
+		WithRootPath(rootDir),
+	)
+
+	require.NoError(t, blz.Open(false))
+	require.NoError(t, blz.Init())
+
+	gRes, err = blz.Get(context.Background(), common.GetPrm{
+		Address:   addr35,
+		StorageID: pRes35.StorageID,
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, obj35, gRes.Object)
+
+	gRes, err = blz.Get(context.Background(), common.GetPrm{
+		Address: addr35,
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, obj35, gRes.Object)
+
+	obj52 := blobstortest.NewObject(10 * 1024)
+	addr52 := objectCore.AddressOf(obj52)
+	raw, err = obj52.Marshal()
+	require.NoError(t, err)
+
+	pRes52, err := blz.Put(context.Background(), common.PutPrm{
+		Address: addr52,
+		Object:  obj52,
+		RawData: raw,
+	})
+	require.NoError(t, err)
+
+	require.NoError(t, blz.Close())
+
+	// change depth and width back
+	blz = NewBlobovniczaTree(
+		WithBlobovniczaShallowDepth(3),
+		WithBlobovniczaShallowWidth(5),
+		WithRootPath(rootDir),
+	)
+	require.NoError(t, blz.Open(false))
+	require.NoError(t, blz.Init())
+
+	gRes, err = blz.Get(context.Background(), common.GetPrm{
+		Address:   addr35,
+		StorageID: pRes35.StorageID,
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, obj35, gRes.Object)
+
+	gRes, err = blz.Get(context.Background(), common.GetPrm{
+		Address: addr35,
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, obj35, gRes.Object)
+
+	gRes, err = blz.Get(context.Background(), common.GetPrm{
+		Address:   addr52,
+		StorageID: pRes52.StorageID,
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, obj52, gRes.Object)
+
+	gRes, err = blz.Get(context.Background(), common.GetPrm{
+		Address: addr52,
+	})
+	require.NoError(t, err)
+	require.EqualValues(t, obj52, gRes.Object)
+
+	require.NoError(t, blz.Close())
+}

pkg/local_object_storage/blobstor/blobovniczatree/delete.go

@@ -3,6 +3,7 @@ package blobovniczatree
 import (
 	"context"
 	"encoding/hex"
+	"errors"
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
@@ -18,6 +19,8 @@ import (
 	"go.uber.org/zap"
 )
 
+var errObjectIsDeleteProtected = errors.New("object is delete protected")
+
 // Delete deletes object from blobovnicza tree.
 //
 // If blobocvnicza ID is specified, only this blobovnicza is processed.
@@ -43,12 +46,22 @@ func (b *Blobovniczas) Delete(ctx context.Context, prm common.DeletePrm) (res co
 		return common.DeleteRes{}, common.ErrReadOnly
 	}
 
+	if b.rebuildGuard.TryRLock() {
+		defer b.rebuildGuard.RUnlock()
+	} else {
+		return common.DeleteRes{}, errRebuildInProgress
+	}
+
+	if b.deleteProtectedObjects.Contains(prm.Address) {
+		return common.DeleteRes{}, errObjectIsDeleteProtected
+	}
+
 	var bPrm blobovnicza.DeletePrm
 	bPrm.SetAddress(prm.Address)
 
 	if prm.StorageID != nil {
-		id := blobovnicza.NewIDFromBytes(prm.StorageID)
+		id := NewIDFromBytes(prm.StorageID)
-		shBlz := b.getBlobovnicza(id.String())
+		shBlz := b.getBlobovnicza(id.Path())
 		blz, err := shBlz.Open()
 		if err != nil {
 			return res, err
@@ -63,7 +76,7 @@ func (b *Blobovniczas) Delete(ctx context.Context, prm common.DeletePrm) (res co
 
 	objectFound := false
 
-	err = b.iterateSortedLeaves(ctx, &prm.Address, func(p string) (bool, error) {
+	err = b.iterateSortedDBPaths(ctx, prm.Address, func(p string) (bool, error) {
 		res, err = b.deleteObjectFromLevel(ctx, bPrm, p)
 		if err != nil {
 			if !client.IsErrObjectNotFound(err) {

pkg/local_object_storage/blobstor/blobovniczatree/exists.go

@@ -36,8 +36,8 @@ func (b *Blobovniczas) Exists(ctx context.Context, prm common.ExistsPrm) (common
 	defer span.End()
 
 	if prm.StorageID != nil {
-		id := blobovnicza.NewIDFromBytes(prm.StorageID)
+		id := NewIDFromBytes(prm.StorageID)
-		shBlz := b.getBlobovnicza(id.String())
+		shBlz := b.getBlobovnicza(id.Path())
 		blz, err := shBlz.Open()
 		if err != nil {
 			return common.ExistsRes{}, err
@@ -51,7 +51,7 @@ func (b *Blobovniczas) Exists(ctx context.Context, prm common.ExistsPrm) (common
 	var gPrm blobovnicza.GetPrm
 	gPrm.SetAddress(prm.Address)
 
-	err := b.iterateSortedLeaves(ctx, &prm.Address, func(p string) (bool, error) {
+	err := b.iterateSortedDBPaths(ctx, prm.Address, func(p string) (bool, error) {
 		_, err := b.getObjectFromLevel(ctx, gPrm, p)
 		if err != nil {
 			if !client.IsErrObjectNotFound(err) {

pkg/local_object_storage/blobstor/blobovniczatree/exists_test.go

@@ -55,7 +55,7 @@ func TestExistsInvalidStorageID(t *testing.T) {
 
 		// An invalid boltdb file is created so that it returns an error when opened
 		require.NoError(t, os.MkdirAll(filepath.Join(dir, relBadFileDir), os.ModePerm))
-		require.NoError(t, os.WriteFile(filepath.Join(dir, relBadFileDir, badFileName), []byte("not a boltdb file content"), 0o777))
+		require.NoError(t, os.WriteFile(filepath.Join(dir, relBadFileDir, badFileName+".db"), []byte("not a boltdb file content"), 0o777))
 
 		res, err := b.Exists(context.Background(), common.ExistsPrm{Address: addr, StorageID: []byte(filepath.Join(relBadFileDir, badFileName))})
 		require.Error(t, err)

pkg/local_object_storage/blobstor/blobovniczatree/get.go

@@ -47,8 +47,8 @@ func (b *Blobovniczas) Get(ctx context.Context, prm common.GetPrm) (res common.G
 	bPrm.SetAddress(prm.Address)
 
 	if prm.StorageID != nil {
-		id := blobovnicza.NewIDFromBytes(prm.StorageID)
+		id := NewIDFromBytes(prm.StorageID)
-		shBlz := b.getBlobovnicza(id.String())
+		shBlz := b.getBlobovnicza(id.Path())
 		blz, err := shBlz.Open()
 		if err != nil {
 			return res, err
@@ -63,7 +63,7 @@ func (b *Blobovniczas) Get(ctx context.Context, prm common.GetPrm) (res common.G
 		return res, err
 	}
 
-	err = b.iterateSortedLeaves(ctx, &prm.Address, func(p string) (bool, error) {
+	err = b.iterateSortedDBPaths(ctx, prm.Address, func(p string) (bool, error) {
 		res, err = b.getObjectFromLevel(ctx, bPrm, p)
 		if err != nil {
 			if !client.IsErrObjectNotFound(err) {

pkg/local_object_storage/blobstor/blobovniczatree/get_range.go

@@ -46,8 +46,8 @@ func (b *Blobovniczas) GetRange(ctx context.Context, prm common.GetRangePrm) (re
 	defer span.End()
 
 	if prm.StorageID != nil {
-		id := blobovnicza.NewIDFromBytes(prm.StorageID)
+		id := NewIDFromBytes(prm.StorageID)
-		shBlz := b.getBlobovnicza(id.String())
+		shBlz := b.getBlobovnicza(id.Path())
 		blz, err := shBlz.Open()
 		if err != nil {
 			return common.GetRangeRes{}, err
@@ -64,7 +64,7 @@ func (b *Blobovniczas) GetRange(ctx context.Context, prm common.GetRangePrm) (re
 
 	objectFound := false
 
-	err = b.iterateSortedLeaves(ctx, &prm.Address, func(p string) (bool, error) {
+	err = b.iterateSortedDBPaths(ctx, prm.Address, func(p string) (bool, error) {
 		res, err = b.getRangeFromLevel(ctx, prm, p)
 		if err != nil {
 			outOfBounds := isErrOutOfRange(err)

pkg/local_object_storage/blobstor/blobovniczatree/id.go

@@ -1,4 +1,4 @@
-package blobovnicza
+package blobovniczatree
 
 // ID represents Blobovnicza identifier.
 type ID []byte
@@ -8,8 +8,8 @@ func NewIDFromBytes(v []byte) *ID {
 	return (*ID)(&v)
 }
 
-func (id ID) String() string {
+func (id ID) Path() string {
-	return string(id)
+	return string(id) + dbExtension
 }
 
 func (id ID) Bytes() []byte {

pkg/local_object_storage/blobstor/blobovniczatree/iterate.go

@@ -3,7 +3,9 @@ package blobovniczatree
 import (
 	"context"
 	"fmt"
+	"os"
 	"path/filepath"
+	"strings"
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
@@ -54,7 +56,7 @@ func (b *Blobovniczas) Iterate(ctx context.Context, prm common.IteratePrm) (comm
 				return prm.Handler(common.IterationElement{
 					Address:    elem.Address(),
 					ObjectData: data,
-					StorageID:  []byte(p),
+					StorageID:  []byte(strings.TrimSuffix(p, dbExtension)),
 				})
 			}
 			return nil
@@ -69,7 +71,7 @@ func (b *Blobovniczas) Iterate(ctx context.Context, prm common.IteratePrm) (comm
 
 // iterator over all Blobovniczas in unsorted order. Break on f's error return.
 func (b *Blobovniczas) iterateBlobovniczas(ctx context.Context, ignoreErrors bool, f func(string, *blobovnicza.Blobovnicza) error) error {
-	return b.iterateLeaves(ctx, func(p string) (bool, error) {
+	return b.iterateExistingDBPaths(ctx, func(p string) (bool, error) {
 		shBlz := b.getBlobovnicza(p)
 		blz, err := shBlz.Open()
 		if err != nil {
@@ -90,7 +92,9 @@ func (b *Blobovniczas) iterateBlobovniczas(ctx context.Context, ignoreErrors boo
 	})
 }
 
-// iterator over the paths of Blobovniczas sorted by weight.
+// iterateSortedLeaves iterates over the paths of Blobovniczas sorted by weight.
+//
+// Uses depth, width and leaf width for iteration.
 func (b *Blobovniczas) iterateSortedLeaves(ctx context.Context, addr *oid.Address, f func(string) (bool, error)) error {
 	_, err := b.iterateSorted(
 		ctx,
@@ -130,7 +134,9 @@ func (b *Blobovniczas) iterateSorted(ctx context.Context, addr *oid.Address, cur
 	}
 	indices := indexSlice(levelWidth)
 
-	hrw.SortSliceByValue(indices, addressHash(addr, filepath.Join(curPath...)))
+	if !isLeafLevel {
+		hrw.SortSliceByValue(indices, addressHash(addr, filepath.Join(curPath...)))
+	}
 
 	exec := uint64(len(curPath)) == execDepth
 
@@ -140,10 +146,16 @@ func (b *Blobovniczas) iterateSorted(ctx context.Context, addr *oid.Address, cur
 			return false, ctx.Err()
 		default:
 		}
+
+		lastPart := u64ToHexString(indices[i])
+		if isLeafLevel {
+			lastPart = u64ToHexStringExt(indices[i])
+		}
+
 		if i == 0 {
-			curPath = append(curPath, u64ToHexString(indices[i]))
+			curPath = append(curPath, lastPart)
 		} else {
-			curPath[len(curPath)-1] = u64ToHexString(indices[i])
+			curPath[len(curPath)-1] = lastPart
 		}
 
 		if exec {
@@ -162,9 +174,110 @@ func (b *Blobovniczas) iterateSorted(ctx context.Context, addr *oid.Address, cur
 	return false, nil
 }
 
-// iterator over the paths of Blobovniczas in random order.
+// iterateExistingDBPaths iterates over the paths of Blobovniczas without any order.
-func (b *Blobovniczas) iterateLeaves(ctx context.Context, f func(string) (bool, error)) error {
+//
-	return b.iterateSortedLeaves(ctx, nil, f)
+// Uses existed blobovnicza files for iteration.
+func (b *Blobovniczas) iterateExistingDBPaths(ctx context.Context, f func(string) (bool, error)) error {
+	b.dbFilesGuard.RLock()
+	defer b.dbFilesGuard.RUnlock()
+
+	_, err := b.iterateExistingDBPathsDFS(ctx, "", f)
+	return err
+}
+
+func (b *Blobovniczas) iterateExistingDBPathsDFS(ctx context.Context, path string, f func(string) (bool, error)) (bool, error) {
+	sysPath := filepath.Join(b.rootPath, path)
+	entries, err := os.ReadDir(sysPath)
+	if os.IsNotExist(err) && b.readOnly && path == "" { // non initialized tree in read only mode
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	for _, entry := range entries {
+		select {
+		case <-ctx.Done():
+			return false, ctx.Err()
+		default:
+		}
+		if entry.IsDir() {
+			stop, err := b.iterateExistingDBPathsDFS(ctx, filepath.Join(path, entry.Name()), f)
+			if err != nil {
+				return false, err
+			}
+			if stop {
+				return true, nil
+			}
+		} else {
+			stop, err := f(filepath.Join(path, entry.Name()))
+			if err != nil {
+				return false, err
+			}
+			if stop {
+				return true, nil
+			}
+		}
+	}
+	return false, nil
+}
+
+func (b *Blobovniczas) iterateSortedDBPaths(ctx context.Context, addr oid.Address, f func(string) (bool, error)) error {
+	b.dbFilesGuard.RLock()
+	defer b.dbFilesGuard.RUnlock()
+
+	_, err := b.iterateSordedDBPathsInternal(ctx, "", addr, f)
+	return err
+}
+
+func (b *Blobovniczas) iterateSordedDBPathsInternal(ctx context.Context, path string, addr oid.Address, f func(string) (bool, error)) (bool, error) {
+	sysPath := filepath.Join(b.rootPath, path)
+	entries, err := os.ReadDir(sysPath)
+	if os.IsNotExist(err) && b.readOnly && path == "" { // non initialized tree in read only mode
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	var dbIdxs []uint64
+	var dirIdxs []uint64
+
+	for _, entry := range entries {
+		idx := u64FromHexString(entry.Name())
+		if entry.IsDir() {
+			dirIdxs = append(dirIdxs, idx)
+		} else {
+			dbIdxs = append(dbIdxs, idx)
+		}
+	}
+
+	if len(dbIdxs) > 0 {
+		for _, dbIdx := range dbIdxs {
+			dbPath := filepath.Join(path, u64ToHexStringExt(dbIdx))
+			stop, err := f(dbPath)
+			if err != nil {
+				return false, err
+			}
+			if stop {
+				return true, nil
+			}
+		}
+	}
+
+	if len(dirIdxs) > 0 {
+		hrw.SortSliceByValue(dirIdxs, addressHash(&addr, path))
+		for _, dirIdx := range dirIdxs {
+			dirPath := filepath.Join(path, u64ToHexString(dirIdx))
+			stop, err := b.iterateSordedDBPathsInternal(ctx, dirPath, addr, f)
+			if err != nil {
+				return false, err
+			}
+			if stop {
+				return true, nil
+			}
+		}
+	}
+
+	return false, nil
 }
 
 // makes slice of uint64 values from 0 to number-1.

pkg/local_object_storage/blobstor/blobovniczatree/iterate_test.go

@@ -0,0 +1,42 @@
+package blobovniczatree
+
+import (
+	"context"
+	"testing"
+
+	oidtest "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestIterateSortedLeavesAndDBPathsAreSame(t *testing.T) {
+	t.Parallel()
+
+	blz := NewBlobovniczaTree(
+		WithBlobovniczaShallowDepth(3),
+		WithBlobovniczaShallowWidth(5),
+		WithRootPath(t.TempDir()),
+	)
+	blz.createDBInAdvance = true
+	require.NoError(t, blz.Open(false))
+	require.NoError(t, blz.Init())
+	defer func() {
+		require.NoError(t, blz.Close())
+	}()
+
+	addr := oidtest.Address()
+
+	var leaves []string
+	var dbPaths []string
+
+	blz.iterateSortedLeaves(context.Background(), &addr, func(s string) (bool, error) {
+		leaves = append(leaves, s)
+		return false, nil
+	})
+
+	blz.iterateSortedDBPaths(context.Background(), addr, func(s string) (bool, error) {
+		dbPaths = append(dbPaths, s)
+		return false, nil
+	})
+
+	require.Equal(t, leaves, dbPaths)
+}

pkg/local_object_storage/blobstor/blobovniczatree/manager.go

@@ -1,7 +1,9 @@
 package blobovniczatree
 
 import (
+	"errors"
 	"fmt"
+	"os"
 	"path/filepath"
 	"sync"
 	"sync/atomic"
@@ -12,9 +14,11 @@ import (
 	"go.uber.org/zap"
 )
 
+var errClosingClosedBlobovnicza = errors.New("closing closed blobovnicza is not allowed")
+
 // sharedDB is responsible for opening and closing a file of single blobovnicza.
 type sharedDB struct {
-	guard    *sync.RWMutex
+	cond     *sync.Cond
 	blcza    *blobovnicza.Blobovnicza
 	refCount uint32
 
@@ -31,8 +35,9 @@ func newSharedDB(options []blobovnicza.Option, path string, readOnly bool,
 	metrics blobovnicza.Metrics, openDBCounter *openDBCounter, closedFlag *atomic.Bool, log *logger.Logger,
 ) *sharedDB {
 	return &sharedDB{
-		guard: &sync.RWMutex{},
+		cond: &sync.Cond{
-
+			L: &sync.RWMutex{},
+		},
 		options:       options,
 		path:          path,
 		readOnly:      readOnly,
@@ -48,8 +53,8 @@ func (b *sharedDB) Open() (*blobovnicza.Blobovnicza, error) {
 		return nil, errClosed
 	}
 
-	b.guard.Lock()
+	b.cond.L.Lock()
-	defer b.guard.Unlock()
+	defer b.cond.L.Unlock()
 
 	if b.refCount > 0 {
 		b.refCount++
@@ -77,11 +82,12 @@ func (b *sharedDB) Open() (*blobovnicza.Blobovnicza, error) {
 }
 
 func (b *sharedDB) Close() {
-	b.guard.Lock()
+	b.cond.L.Lock()
-	defer b.guard.Unlock()
+	defer b.cond.L.Unlock()
 
 	if b.refCount == 0 {
 		b.log.Error(logs.AttemtToCloseAlreadyClosedBlobovnicza, zap.String("id", b.path))
+		b.cond.Broadcast()
 		return
 	}
 
@@ -99,33 +105,109 @@ func (b *sharedDB) Close() {
 	}
 
 	b.refCount--
+	if b.refCount == 1 {
+		b.cond.Broadcast()
+	}
 }
 
-func (b *sharedDB) Path() string {
+func (b *sharedDB) CloseAndRemoveFile() error {
+	b.cond.L.Lock()
+	if b.refCount > 1 {
+		b.cond.Wait()
+	}
+	defer b.cond.L.Unlock()
+
+	if b.refCount == 0 {
+		return errClosingClosedBlobovnicza
+	}
+
+	if err := b.blcza.Close(); err != nil {
+		b.log.Error(logs.BlobovniczatreeCouldNotCloseBlobovnicza,
+			zap.String("id", b.path),
+			zap.String("error", err.Error()),
+		)
+		return fmt.Errorf("failed to close blobovnicza (path = %s): %w", b.path, err)
+	}
+
+	b.refCount = 0
+	b.blcza = nil
+	b.openDBCounter.Dec()
+
+	return os.Remove(b.path)
+}
+
+func (b *sharedDB) SystemPath() string {
 	return b.path
 }
 
 // levelDbManager stores pointers of the sharedDB's for the leaf directory of the blobovnicza tree.
 type levelDbManager struct {
-	databases []*sharedDB
+	dbMtx     *sync.RWMutex
+	databases map[uint64]*sharedDB
+
+	options       []blobovnicza.Option
+	path          string
+	readOnly      bool
+	metrics       blobovnicza.Metrics
+	openDBCounter *openDBCounter
+	closedFlag    *atomic.Bool
+	log           *logger.Logger
 }
 
-func newLevelDBManager(width uint64, options []blobovnicza.Option, rootPath string, lvlPath string,
+func newLevelDBManager(options []blobovnicza.Option, rootPath string, lvlPath string,
-	readOnly bool, metrics blobovnicza.Metrics, openDBCounter *openDBCounter, closedFlog *atomic.Bool, log *logger.Logger,
+	readOnly bool, metrics blobovnicza.Metrics, openDBCounter *openDBCounter, closedFlag *atomic.Bool, log *logger.Logger,
 ) *levelDbManager {
 	result := &levelDbManager{
-		databases: make([]*sharedDB, width),
+		databases: make(map[uint64]*sharedDB),
-	}
+		dbMtx:     &sync.RWMutex{},
-	for idx := uint64(0); idx < width; idx++ {
+
-		result.databases[idx] = newSharedDB(options, filepath.Join(rootPath, lvlPath, u64ToHexString(idx)), readOnly, metrics, openDBCounter, closedFlog, log)
+		options:       options,
+		path:          filepath.Join(rootPath, lvlPath),
+		readOnly:      readOnly,
+		metrics:       metrics,
+		openDBCounter: openDBCounter,
+		closedFlag:    closedFlag,
+		log:           log,
 	}
 	return result
 }
 
 func (m *levelDbManager) GetByIndex(idx uint64) *sharedDB {
+	res := m.getDBIfExists(idx)
+	if res != nil {
+		return res
+	}
+	return m.getOrCreateDB(idx)
+}
+
+func (m *levelDbManager) getDBIfExists(idx uint64) *sharedDB {
+	m.dbMtx.RLock()
+	defer m.dbMtx.RUnlock()
+
 	return m.databases[idx]
 }
 
+func (m *levelDbManager) getOrCreateDB(idx uint64) *sharedDB {
+	m.dbMtx.Lock()
+	defer m.dbMtx.Unlock()
+
+	db := m.databases[idx]
+	if db != nil {
+		return db
+	}
+
+	db = newSharedDB(m.options, filepath.Join(m.path, u64ToHexStringExt(idx)), m.readOnly, m.metrics, m.openDBCounter, m.closedFlag, m.log)
+	m.databases[idx] = db
+	return db
+}
+
+func (m *levelDbManager) hasAnyDB() bool {
+	m.dbMtx.RLock()
+	defer m.dbMtx.RUnlock()
+
+	return len(m.databases) > 0
+}
+
 // dbManager manages the opening and closing of blobovnicza instances.
 //
 // The blobovnicza opens at the first request, closes after the last request.
@@ -135,21 +217,19 @@ type dbManager struct {
 	closedFlag          *atomic.Bool
 	dbCounter           *openDBCounter
 
-	rootPath  string
+	rootPath string
-	options   []blobovnicza.Option
+	options  []blobovnicza.Option
-	readOnly  bool
+	readOnly bool
-	metrics   blobovnicza.Metrics
+	metrics  blobovnicza.Metrics
-	leafWidth uint64
+	log      *logger.Logger
-	log       *logger.Logger
 }
 
-func newDBManager(rootPath string, options []blobovnicza.Option, leafWidth uint64, readOnly bool, metrics blobovnicza.Metrics, log *logger.Logger) *dbManager {
+func newDBManager(rootPath string, options []blobovnicza.Option, readOnly bool, metrics blobovnicza.Metrics, log *logger.Logger) *dbManager {
 	return &dbManager{
 		rootPath:            rootPath,
 		options:             options,
 		readOnly:            readOnly,
 		metrics:             metrics,
-		leafWidth:           leafWidth,
 		levelToManager:      make(map[string]*levelDbManager),
 		levelToManagerGuard: &sync.RWMutex{},
 		log:                 log,
@@ -165,6 +245,17 @@ func (m *dbManager) GetByPath(path string) *sharedDB {
 	return levelManager.GetByIndex(curIndex)
 }
 
+func (m *dbManager) CleanResources(path string) {
+	lvlPath := filepath.Dir(path)
+
+	m.levelToManagerGuard.Lock()
+	defer m.levelToManagerGuard.Unlock()
+
+	if result, ok := m.levelToManager[lvlPath]; ok && !result.hasAnyDB() {
+		delete(m.levelToManager, lvlPath)
+	}
+}
+
 func (m *dbManager) Open() {
 	m.closedFlag.Store(false)
 }
@@ -197,7 +288,7 @@ func (m *dbManager) getOrCreateLevelManager(lvlPath string) *levelDbManager {
 		return result
 	}
 
-	result := newLevelDBManager(m.leafWidth, m.options, m.rootPath, lvlPath, m.readOnly, m.metrics, m.dbCounter, m.closedFlag, m.log)
+	result := newLevelDBManager(m.options, m.rootPath, lvlPath, m.readOnly, m.metrics, m.dbCounter, m.closedFlag, m.log)
 	m.levelToManager[lvlPath] = result
 	return result
 }

pkg/local_object_storage/blobstor/blobovniczatree/metrics.go

@@ -6,6 +6,13 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobovnicza"
 )
 
+const (
+	rebuildStatusNotStarted = "not_started"
+	rebuildStatusRunning    = "running"
+	rebuildStatusCompleted  = "completed"
+	rebuildStatusFailed     = "failed"
+)
+
 type Metrics interface {
 	Blobovnicza() blobovnicza.Metrics
 
@@ -14,6 +21,10 @@ type Metrics interface {
 	SetMode(readOnly bool)
 	Close()
 
+	SetRebuildStatus(status string)
+	ObjectMoved(d time.Duration)
+	SetRebuildPercent(value uint32)
+
 	Delete(d time.Duration, success, withStorageID bool)
 	Exists(d time.Duration, success, withStorageID bool)
 	GetRange(d time.Duration, size int, success, withStorageID bool)
@@ -27,6 +38,9 @@ type noopMetrics struct{}
 func (m *noopMetrics) SetParentID(string)                      {}
 func (m *noopMetrics) SetMode(bool)                            {}
 func (m *noopMetrics) Close()                                  {}
+func (m *noopMetrics) SetRebuildStatus(string)                 {}
+func (m *noopMetrics) SetRebuildPercent(uint32)                {}
+func (m *noopMetrics) ObjectMoved(time.Duration)               {}
 func (m *noopMetrics) Delete(time.Duration, bool, bool)        {}
 func (m *noopMetrics) Exists(time.Duration, bool, bool)        {}
 func (m *noopMetrics) GetRange(time.Duration, int, bool, bool) {}

pkg/local_object_storage/blobstor/blobovniczatree/option.go

@@ -2,6 +2,7 @@ package blobovniczatree
 
 import (
 	"io/fs"
+	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobovnicza"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/compression"
@@ -10,39 +11,48 @@ import (
 )
 
 type cfg struct {
-	log             *logger.Logger
+	log                *logger.Logger
-	perm            fs.FileMode
+	perm               fs.FileMode
-	readOnly        bool
+	readOnly           bool
-	rootPath        string
+	rootPath           string
-	openedCacheSize int
+	openedCacheSize    int
-	blzShallowDepth uint64
+	blzShallowDepth    uint64
-	blzShallowWidth uint64
+	blzShallowWidth    uint64
-	blzLeafWidth    uint64
+	blzLeafWidth       uint64
-	compression     *compression.Config
+	compression        *compression.Config
-	blzOpts         []blobovnicza.Option
+	blzOpts            []blobovnicza.Option
-	// reportError is the function called when encountering disk errors.
+	reportError        func(string, error) // reportError is the function called when encountering disk errors.
-	reportError func(string, error)
+	metrics            Metrics
-	metrics     Metrics
+	waitBeforeDropDB   time.Duration
+	blzInitWorkerCount int
+	blzMoveBatchSize   int
+	createDBInAdvance  bool
 }
 
 type Option func(*cfg)
 
 const (
-	defaultPerm            = 0o700
+	defaultPerm               = 0o700
-	defaultOpenedCacheSize = 50
+	defaultOpenedCacheSize    = 50
-	defaultBlzShallowDepth = 2
+	defaultBlzShallowDepth    = 2
-	defaultBlzShallowWidth = 16
+	defaultBlzShallowWidth    = 16
+	defaultWaitBeforeDropDB   = 10 * time.Second
+	defaultBlzInitWorkerCount = 5
+	defaulBlzMoveBatchSize    = 10000
 )
 
 func initConfig(c *cfg) {
 	*c = cfg{
-		log:             &logger.Logger{Logger: zap.L()},
+		log:                &logger.Logger{Logger: zap.L()},
-		perm:            defaultPerm,
+		perm:               defaultPerm,
-		openedCacheSize: defaultOpenedCacheSize,
+		openedCacheSize:    defaultOpenedCacheSize,
-		blzShallowDepth: defaultBlzShallowDepth,
+		blzShallowDepth:    defaultBlzShallowDepth,
-		blzShallowWidth: defaultBlzShallowWidth,
+		blzShallowWidth:    defaultBlzShallowWidth,
-		reportError:     func(string, error) {},
+		reportError:        func(string, error) {},
-		metrics:         &noopMetrics{},
+		metrics:            &noopMetrics{},
+		waitBeforeDropDB:   defaultWaitBeforeDropDB,
+		blzInitWorkerCount: defaultBlzInitWorkerCount,
+		blzMoveBatchSize:   defaulBlzMoveBatchSize,
 	}
 }
 
@@ -106,3 +116,34 @@ func WithMetrics(m Metrics) Option {
 		c.metrics = m
 	}
 }
+
+func WithWaitBeforeDropDB(t time.Duration) Option {
+	return func(c *cfg) {
+		c.waitBeforeDropDB = t
+	}
+}
+
+func WithMoveBatchSize(v int) Option {
+	return func(c *cfg) {
+		c.blzMoveBatchSize = v
+	}
+}
+
+// WithInitWorkerCount sets maximum workers count to init blobovnicza tree.
+//
+// Negative or zero value means no limit.
+func WithInitWorkerCount(v int) Option {
+	if v <= 0 {
+		v = -1
+	}
+	return func(c *cfg) {
+		c.blzInitWorkerCount = v
+	}
+}
+
+// WithInitInAdvance returns an option to create blobovnicza tree DB's in advance.
+func WithInitInAdvance(v bool) Option {
+	return func(c *cfg) {
+		c.createDBInAdvance = v
+	}
+}

pkg/local_object_storage/blobstor/blobovniczatree/put.go

@@ -70,7 +70,7 @@ func (b *Blobovniczas) Put(ctx context.Context, prm common.PutPrm) (common.PutRe
 
 type putIterator struct {
 	B       *Blobovniczas
-	ID      *blobovnicza.ID
+	ID      *ID
 	AllFull bool
 	PutPrm  blobovnicza.PutPrm
 }
@@ -104,7 +104,7 @@ func (i *putIterator) iterate(ctx context.Context, lvlPath string) (bool, error)
 			i.B.reportError(logs.BlobovniczatreeCouldNotPutObjectToActiveBlobovnicza, err)
 		} else {
 			i.B.log.Debug(logs.BlobovniczatreeCouldNotPutObjectToActiveBlobovnicza,
-				zap.String("path", active.Path()),
+				zap.String("path", active.SystemPath()),
 				zap.String("error", err.Error()),
 				zap.String("trace_id", tracingPkg.GetTraceID(ctx)))
 		}
@@ -112,8 +112,8 @@ func (i *putIterator) iterate(ctx context.Context, lvlPath string) (bool, error)
 		return false, nil
 	}
 
-	idx := u64FromHexString(filepath.Base(active.Path()))
+	idx := u64FromHexString(filepath.Base(active.SystemPath()))
-	i.ID = blobovnicza.NewIDFromBytes([]byte(filepath.Join(lvlPath, u64ToHexString(idx))))
+	i.ID = NewIDFromBytes([]byte(filepath.Join(lvlPath, u64ToHexString(idx))))
 
 	return true, nil
 }

pkg/local_object_storage/blobstor/blobovniczatree/rebuild.go

@@ -0,0 +1,478 @@
+package blobovniczatree
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"os"
+	"path/filepath"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobovnicza"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"go.uber.org/zap"
+	"golang.org/x/sync/errgroup"
+)
+
+var (
+	errRebuildInProgress = errors.New("rebuild is in progress, the operation cannot be performed")
+	errBatchFull         = errors.New("batch full")
+)
+
+func (b *Blobovniczas) Rebuild(ctx context.Context, prm common.RebuildPrm) (common.RebuildRes, error) {
+	if b.readOnly {
+		return common.RebuildRes{}, common.ErrReadOnly
+	}
+
+	b.metrics.SetRebuildStatus(rebuildStatusRunning)
+	b.metrics.SetRebuildPercent(0)
+	success := true
+	defer func() {
+		if success {
+			b.metrics.SetRebuildStatus(rebuildStatusCompleted)
+		} else {
+			b.metrics.SetRebuildStatus(rebuildStatusFailed)
+		}
+	}()
+
+	b.rebuildGuard.Lock()
+	defer b.rebuildGuard.Unlock()
+
+	var res common.RebuildRes
+
+	b.log.Debug(logs.BlobovniczaTreeCompletingPreviousRebuild)
+	completedPreviosMoves, err := b.completeIncompletedMove(ctx, prm.MetaStorage)
+	res.ObjectsMoved += completedPreviosMoves
+	if err != nil {
+		b.log.Warn(logs.BlobovniczaTreeCompletedPreviousRebuildFailed, zap.Error(err))
+		success = false
+		return res, err
+	}
+	b.log.Debug(logs.BlobovniczaTreeCompletedPreviousRebuildSuccess)
+
+	b.log.Debug(logs.BlobovniczaTreeCollectingDBToRebuild)
+	dbsToMigrate, err := b.getDBsToRebuild(ctx)
+	if err != nil {
+		b.log.Warn(logs.BlobovniczaTreeCollectingDBToRebuildFailed, zap.Error(err))
+		success = false
+		return res, err
+	}
+
+	b.log.Info(logs.BlobovniczaTreeCollectingDBToRebuildSuccess, zap.Int("blobovniczas_to_rebuild", len(dbsToMigrate)))
+	res, err = b.migrateDBs(ctx, dbsToMigrate, prm, res)
+	if err != nil {
+		success = false
+	}
+	return res, err
+}
+
+func (b *Blobovniczas) migrateDBs(ctx context.Context, dbs []string, prm common.RebuildPrm, res common.RebuildRes) (common.RebuildRes, error) {
+	var completedDBCount uint32
+	for _, db := range dbs {
+		b.log.Debug(logs.BlobovniczaTreeRebuildingBlobovnicza, zap.String("path", db))
+		movedObjects, err := b.rebuildDB(ctx, db, prm.MetaStorage, prm.WorkerLimiter)
+		res.ObjectsMoved += movedObjects
+		if err != nil {
+			b.log.Warn(logs.BlobovniczaTreeRebuildingBlobovniczaFailed, zap.String("path", db), zap.Uint64("moved_objects_count", movedObjects), zap.Error(err))
+			return res, err
+		}
+		b.log.Debug(logs.BlobovniczaTreeRebuildingBlobovniczaSuccess, zap.String("path", db), zap.Uint64("moved_objects_count", movedObjects))
+		res.FilesRemoved++
+		completedDBCount++
+		b.metrics.SetRebuildPercent((100 * completedDBCount) / uint32(len(dbs)))
+	}
+	b.metrics.SetRebuildPercent(100)
+	return res, nil
+}
+
+func (b *Blobovniczas) getDBsToRebuild(ctx context.Context) ([]string, error) {
+	dbsToMigrate := make(map[string]struct{})
+	if err := b.iterateExistingDBPaths(ctx, func(s string) (bool, error) {
+		dbsToMigrate[s] = struct{}{}
+		return false, nil
+	}); err != nil {
+		return nil, err
+	}
+	if err := b.iterateSortedLeaves(ctx, nil, func(s string) (bool, error) {
+		delete(dbsToMigrate, s)
+		return false, nil
+	}); err != nil {
+		return nil, err
+	}
+	result := make([]string, 0, len(dbsToMigrate))
+	for db := range dbsToMigrate {
+		result = append(result, db)
+	}
+	return result, nil
+}
+
+func (b *Blobovniczas) rebuildDB(ctx context.Context, path string, meta common.MetaStorage, limiter common.ConcurrentWorkersLimiter) (uint64, error) {
+	shDB := b.getBlobovnicza(path)
+	blz, err := shDB.Open()
+	if err != nil {
+		return 0, err
+	}
+	shDBClosed := false
+	defer func() {
+		if shDBClosed {
+			return
+		}
+		shDB.Close()
+	}()
+
+	migratedObjects, err := b.moveObjects(ctx, blz, shDB.SystemPath(), meta, limiter)
+	if err != nil {
+		return migratedObjects, err
+	}
+	shDBClosed, err = b.dropDB(ctx, path, shDB)
+	return migratedObjects, err
+}
+
+func (b *Blobovniczas) moveObjects(ctx context.Context, blz *blobovnicza.Blobovnicza, blzPath string, meta common.MetaStorage, limiter common.ConcurrentWorkersLimiter) (uint64, error) {
+	var result atomic.Uint64
+	batch := make(map[oid.Address][]byte)
+
+	var prm blobovnicza.IteratePrm
+	prm.DecodeAddresses()
+	prm.SetHandler(func(ie blobovnicza.IterationElement) error {
+		batch[ie.Address()] = bytes.Clone(ie.ObjectData())
+		if len(batch) == b.blzMoveBatchSize {
+			return errBatchFull
+		}
+		return nil
+	})
+
+	for {
+		_, err := blz.Iterate(ctx, prm)
+		if err != nil && !errors.Is(err, errBatchFull) {
+			return result.Load(), err
+		}
+
+		if len(batch) == 0 {
+			break
+		}
+
+		eg, egCtx := errgroup.WithContext(ctx)
+
+		for addr, data := range batch {
+			addr := addr
+			data := data
+
+			if err := limiter.AcquireWorkSlot(egCtx); err != nil {
+				_ = eg.Wait()
+				return result.Load(), err
+			}
+			eg.Go(func() error {
+				defer limiter.ReleaseWorkSlot()
+				err := b.moveObject(egCtx, blz, blzPath, addr, data, meta)
+				if err == nil {
+					result.Add(1)
+				}
+				return err
+			})
+		}
+		if err := eg.Wait(); err != nil {
+			return result.Load(), err
+		}
+
+		batch = make(map[oid.Address][]byte)
+	}
+
+	return result.Load(), nil
+}
+
+func (b *Blobovniczas) moveObject(ctx context.Context, source *blobovnicza.Blobovnicza, sourcePath string,
+	addr oid.Address, data []byte, metaStore common.MetaStorage,
+) error {
+	startedAt := time.Now()
+	defer func() {
+		b.metrics.ObjectMoved(time.Since(startedAt))
+	}()
+	it := &moveIterator{
+		B:             b,
+		ID:            nil,
+		AllFull:       true,
+		Address:       addr,
+		ObjectData:    data,
+		MetaStore:     metaStore,
+		Source:        source,
+		SourceSysPath: sourcePath,
+	}
+
+	if err := b.iterateDeepest(ctx, addr, func(lvlPath string) (bool, error) { return it.tryMoveToLvl(ctx, lvlPath) }); err != nil {
+		return err
+	} else if it.ID == nil {
+		if it.AllFull {
+			return common.ErrNoSpace
+		}
+		return errPutFailed
+	}
+	return nil
+}
+
+func (b *Blobovniczas) dropDB(ctx context.Context, path string, shDb *sharedDB) (bool, error) {
+	select {
+	case <-ctx.Done():
+		return false, ctx.Err()
+	case <-time.After(b.waitBeforeDropDB): // to complete requests with old storage ID
+	}
+
+	b.dbCache.EvictAndMarkNonCached(path)
+	defer b.dbCache.RemoveFromNonCached(path)
+
+	b.dbFilesGuard.Lock()
+	defer b.dbFilesGuard.Unlock()
+
+	if err := shDb.CloseAndRemoveFile(); err != nil {
+		return false, err
+	}
+	b.commondbManager.CleanResources(path)
+	if err := b.dropDirectoryIfEmpty(filepath.Dir(path)); err != nil {
+		return true, err
+	}
+	return true, nil
+}
+
+func (b *Blobovniczas) dropDirectoryIfEmpty(path string) error {
+	if path == "." {
+		return nil
+	}
+
+	sysPath := filepath.Join(b.rootPath, path)
+	entries, err := os.ReadDir(sysPath)
+	if err != nil {
+		return err
+	}
+	if len(entries) > 0 {
+		return nil
+	}
+	if err := os.Remove(sysPath); err != nil {
+		return err
+	}
+	return b.dropDirectoryIfEmpty(filepath.Dir(path))
+}
+
+func (b *Blobovniczas) completeIncompletedMove(ctx context.Context, metaStore common.MetaStorage) (uint64, error) {
+	var count uint64
+	return count, b.iterateExistingDBPaths(ctx, func(s string) (bool, error) {
+		shDB := b.getBlobovnicza(s)
+		blz, err := shDB.Open()
+		if err != nil {
+			return true, err
+		}
+		defer shDB.Close()
+
+		incompletedMoves, err := blz.ListMoveInfo(ctx)
+		if err != nil {
+			return true, err
+		}
+
+		for _, move := range incompletedMoves {
+			if err := b.performMove(ctx, blz, shDB.SystemPath(), move, metaStore); err != nil {
+				return true, err
+			}
+			count++
+		}
+
+		return false, nil
+	})
+}
+
+func (b *Blobovniczas) performMove(ctx context.Context, source *blobovnicza.Blobovnicza, sourcePath string,
+	move blobovnicza.MoveInfo, metaStore common.MetaStorage,
+) error {
+	targetDB := b.getBlobovnicza(NewIDFromBytes(move.TargetStorageID).Path())
+	target, err := targetDB.Open()
+	if err != nil {
+		return err
+	}
+	defer targetDB.Close()
+
+	existsInSource := true
+	var gPrm blobovnicza.GetPrm
+	gPrm.SetAddress(move.Address)
+	gRes, err := source.Get(ctx, gPrm)
+	if err != nil {
+		if client.IsErrObjectNotFound(err) {
+			existsInSource = false
+		} else {
+			b.log.Warn(logs.BlobovniczatreeCouldNotCheckExistenceInTargetDB, zap.Error(err))
+			return err
+		}
+	}
+
+	if !existsInSource { // object was deleted by Rebuild, need to delete move info
+		if err = source.DropMoveInfo(ctx, move.Address); err != nil {
+			b.log.Warn(logs.BlobovniczatreeCouldNotDropMoveInfo, zap.String("path", sourcePath), zap.Error(err))
+			return err
+		}
+		b.deleteProtectedObjects.Delete(move.Address)
+		return nil
+	}
+
+	existsInTarget, err := target.Exists(ctx, move.Address)
+	if err != nil {
+		b.log.Warn(logs.BlobovniczatreeCouldNotCheckExistenceInTargetDB, zap.Error(err))
+		return err
+	}
+
+	if !existsInTarget {
+		var putPrm blobovnicza.PutPrm
+		putPrm.SetAddress(move.Address)
+		putPrm.SetMarshaledObject(gRes.Object())
+		_, err = target.Put(ctx, putPrm)
+		if err != nil {
+			b.log.Warn(logs.BlobovniczatreeCouldNotPutObjectToTargetDB, zap.String("path", targetDB.SystemPath()), zap.Error(err))
+			return err
+		}
+	}
+
+	if err = metaStore.UpdateStorageID(ctx, move.Address, move.TargetStorageID); err != nil {
+		b.log.Warn(logs.BlobovniczatreeCouldNotUpdateStorageID, zap.Error(err), zap.Stringer("address", move.Address))
+		return err
+	}
+
+	var deletePrm blobovnicza.DeletePrm
+	deletePrm.SetAddress(move.Address)
+	if _, err = source.Delete(ctx, deletePrm); err != nil {
+		b.log.Warn(logs.BlobovniczatreeCouldNotDeleteFromSource, zap.String("path", sourcePath), zap.Error(err))
+		return err
+	}
+
+	if err = source.DropMoveInfo(ctx, move.Address); err != nil {
+		b.log.Warn(logs.BlobovniczatreeCouldNotDropMoveInfo, zap.String("path", sourcePath), zap.Error(err))
+		return err
+	}
+
+	b.deleteProtectedObjects.Delete(move.Address)
+	return nil
+}
+
+type moveIterator struct {
+	B             *Blobovniczas
+	ID            *ID
+	AllFull       bool
+	Address       oid.Address
+	ObjectData    []byte
+	MetaStore     common.MetaStorage
+	Source        *blobovnicza.Blobovnicza
+	SourceSysPath string
+}
+
+func (i *moveIterator) tryMoveToLvl(ctx context.Context, lvlPath string) (bool, error) {
+	target, err := i.B.activeDBManager.GetOpenedActiveDBForLevel(lvlPath)
+	if err != nil {
+		if !isLogical(err) {
+			i.B.reportError(logs.BlobovniczatreeCouldNotGetActiveBlobovnicza, err)
+		} else {
+			i.B.log.Warn(logs.BlobovniczatreeCouldNotGetActiveBlobovnicza, zap.Error(err))
+		}
+		return false, nil
+	}
+
+	if target == nil {
+		i.B.log.Warn(logs.BlobovniczatreeBlobovniczaOverflowed, zap.String("level", lvlPath))
+		return false, nil
+	}
+	defer target.Close()
+
+	i.AllFull = false
+
+	targetIDx := u64FromHexString(filepath.Base(target.SystemPath()))
+	targetStorageID := NewIDFromBytes([]byte(filepath.Join(lvlPath, u64ToHexString(targetIDx))))
+
+	if err = i.Source.PutMoveInfo(ctx, blobovnicza.MoveInfo{
+		Address:         i.Address,
+		TargetStorageID: targetStorageID.Bytes(),
+	}); err != nil {
+		if !isLogical(err) {
+			i.B.reportError(logs.BlobovniczatreeCouldNotPutMoveInfoToSourceBlobovnicza, err)
+		} else {
+			i.B.log.Warn(logs.BlobovniczatreeCouldNotPutMoveInfoToSourceBlobovnicza, zap.String("path", i.SourceSysPath), zap.Error(err))
+		}
+		return true, nil
+	}
+	i.B.deleteProtectedObjects.Add(i.Address)
+
+	var putPrm blobovnicza.PutPrm
+	putPrm.SetAddress(i.Address)
+	putPrm.SetMarshaledObject(i.ObjectData)
+
+	_, err = target.Blobovnicza().Put(ctx, putPrm)
+	if err != nil {
+		if !isLogical(err) {
+			i.B.reportError(logs.BlobovniczatreeCouldNotPutObjectToActiveBlobovnicza, err)
+		} else {
+			i.B.log.Warn(logs.BlobovniczatreeCouldNotPutObjectToActiveBlobovnicza, zap.String("path", target.SystemPath()), zap.Error(err))
+		}
+		return true, nil
+	}
+
+	if err = i.MetaStore.UpdateStorageID(ctx, i.Address, targetStorageID.Bytes()); err != nil {
+		i.B.log.Warn(logs.BlobovniczatreeCouldNotUpdateStorageID, zap.Error(err), zap.Stringer("address", i.Address))
+		return true, nil
+	}
+
+	var deletePrm blobovnicza.DeletePrm
+	deletePrm.SetAddress(i.Address)
+	if _, err = i.Source.Delete(ctx, deletePrm); err != nil {
+		if !isLogical(err) {
+			i.B.reportError(logs.BlobovniczatreeCouldNotDeleteFromSource, err)
+		} else {
+			i.B.log.Warn(logs.BlobovniczatreeCouldNotDeleteFromSource, zap.String("path", i.SourceSysPath), zap.Error(err))
+		}
+		return true, nil
+	}
+
+	if err = i.Source.DropMoveInfo(ctx, i.Address); err != nil {
+		if !isLogical(err) {
+			i.B.reportError(logs.BlobovniczatreeCouldNotDropMoveInfo, err)
+		} else {
+			i.B.log.Warn(logs.BlobovniczatreeCouldNotDropMoveInfo, zap.String("path", i.SourceSysPath), zap.Error(err))
+		}
+		return true, nil
+	}
+	i.B.deleteProtectedObjects.Delete(i.Address)
+
+	i.ID = targetStorageID
+	return true, nil
+}
+
+type addressMap struct {
+	data  map[oid.Address]struct{}
+	guard *sync.RWMutex
+}
+
+func newAddressMap() *addressMap {
+	return &addressMap{
+		data:  make(map[oid.Address]struct{}),
+		guard: &sync.RWMutex{},
+	}
+}
+
+func (m *addressMap) Add(address oid.Address) {
+	m.guard.Lock()
+	defer m.guard.Unlock()
+
+	m.data[address] = struct{}{}
+}
+
+func (m *addressMap) Delete(address oid.Address) {
+	m.guard.Lock()
+	defer m.guard.Unlock()
+
+	delete(m.data, address)
+}
+
+func (m *addressMap) Contains(address oid.Address) bool {
+	m.guard.RLock()
+	defer m.guard.RUnlock()
+
+	_, contains := m.data[address]
+	return contains
+}

pkg/local_object_storage/blobstor/blobovniczatree/rebuild_failover_test.go

@@ -0,0 +1,195 @@
+package blobovniczatree
+
+import (
+	"bytes"
+	"context"
+	"path/filepath"
+	"sync"
+	"testing"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobovnicza"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/internal/blobstortest"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger/test"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client"
+	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"github.com/stretchr/testify/require"
+)
+
+func TestRebuildFailover(t *testing.T) {
+	t.Parallel()
+
+	t.Run("only move info saved", testRebuildFailoverOnlyMoveInfoSaved)
+
+	t.Run("object saved to target", testRebuildFailoverObjectSavedToTarget)
+
+	t.Run("object deleted from source", testRebuildFailoverObjectDeletedFromSource)
+}
+
+func testRebuildFailoverOnlyMoveInfoSaved(t *testing.T) {
+	t.Parallel()
+	dir := t.TempDir()
+
+	blz := blobovnicza.New(blobovnicza.WithPath(filepath.Join(dir, "0", "0", "1.db")))
+	require.NoError(t, blz.Open())
+	require.NoError(t, blz.Init())
+
+	obj := blobstortest.NewObject(1024)
+	data, err := obj.Marshal()
+	require.NoError(t, err)
+
+	var pPrm blobovnicza.PutPrm
+	pPrm.SetAddress(object.AddressOf(obj))
+	pPrm.SetMarshaledObject(data)
+	_, err = blz.Put(context.Background(), pPrm)
+	require.NoError(t, err)
+
+	require.NoError(t, blz.PutMoveInfo(context.Background(), blobovnicza.MoveInfo{
+		Address:         object.AddressOf(obj),
+		TargetStorageID: []byte("0/0/0"),
+	}))
+
+	require.NoError(t, blz.Close())
+
+	testRebuildFailoverValidate(t, dir, obj, true)
+}
+
+func testRebuildFailoverObjectSavedToTarget(t *testing.T) {
+	t.Parallel()
+	dir := t.TempDir()
+
+	blz := blobovnicza.New(blobovnicza.WithPath(filepath.Join(dir, "0", "0", "1.db")))
+	require.NoError(t, blz.Open())
+	require.NoError(t, blz.Init())
+
+	obj := blobstortest.NewObject(1024)
+	data, err := obj.Marshal()
+	require.NoError(t, err)
+
+	var pPrm blobovnicza.PutPrm
+	pPrm.SetAddress(object.AddressOf(obj))
+	pPrm.SetMarshaledObject(data)
+	_, err = blz.Put(context.Background(), pPrm)
+	require.NoError(t, err)
+
+	require.NoError(t, blz.PutMoveInfo(context.Background(), blobovnicza.MoveInfo{
+		Address:         object.AddressOf(obj),
+		TargetStorageID: []byte("0/0/0"),
+	}))
+
+	require.NoError(t, blz.Close())
+
+	blz = blobovnicza.New(blobovnicza.WithPath(filepath.Join(dir, "0", "0", "0.db")))
+	require.NoError(t, blz.Open())
+	require.NoError(t, blz.Init())
+
+	_, err = blz.Put(context.Background(), pPrm)
+	require.NoError(t, err)
+
+	require.NoError(t, blz.Close())
+
+	testRebuildFailoverValidate(t, dir, obj, true)
+}
+
+func testRebuildFailoverObjectDeletedFromSource(t *testing.T) {
+	t.Parallel()
+	dir := t.TempDir()
+
+	blz := blobovnicza.New(blobovnicza.WithPath(filepath.Join(dir, "0", "0", "1.db")))
+	require.NoError(t, blz.Open())
+	require.NoError(t, blz.Init())
+
+	obj := blobstortest.NewObject(1024)
+	data, err := obj.Marshal()
+	require.NoError(t, err)
+
+	require.NoError(t, blz.PutMoveInfo(context.Background(), blobovnicza.MoveInfo{
+		Address:         object.AddressOf(obj),
+		TargetStorageID: []byte("0/0/0"),
+	}))
+
+	require.NoError(t, blz.Close())
+
+	blz = blobovnicza.New(blobovnicza.WithPath(filepath.Join(dir, "0", "0", "0.db")))
+	require.NoError(t, blz.Open())
+	require.NoError(t, blz.Init())
+
+	var pPrm blobovnicza.PutPrm
+	pPrm.SetAddress(object.AddressOf(obj))
+	pPrm.SetMarshaledObject(data)
+	_, err = blz.Put(context.Background(), pPrm)
+	require.NoError(t, err)
+
+	require.NoError(t, blz.Close())
+
+	testRebuildFailoverValidate(t, dir, obj, false)
+}
+
+func testRebuildFailoverValidate(t *testing.T, dir string, obj *objectSDK.Object, mustUpdateStorageID bool) {
+	b := NewBlobovniczaTree(
+		WithLogger(test.NewLogger(t, true)),
+		WithObjectSizeLimit(2048),
+		WithBlobovniczaShallowWidth(2),
+		WithBlobovniczaShallowDepth(2),
+		WithRootPath(dir),
+		WithBlobovniczaSize(100*1024*1024),
+		WithWaitBeforeDropDB(0),
+		WithOpenedCacheSize(1000))
+	require.NoError(t, b.Open(false))
+	require.NoError(t, b.Init())
+
+	var dPrm common.DeletePrm
+	dPrm.Address = object.AddressOf(obj)
+	dPrm.StorageID = []byte("0/0/1")
+	_, err := b.Delete(context.Background(), dPrm)
+	require.ErrorIs(t, err, errObjectIsDeleteProtected)
+
+	metaStub := &storageIDUpdateStub{
+		storageIDs: make(map[oid.Address][]byte),
+		guard:      &sync.Mutex{},
+	}
+	rRes, err := b.Rebuild(context.Background(), common.RebuildPrm{
+		MetaStorage:   metaStub,
+		WorkerLimiter: &rebuildLimiterStub{},
+	})
+	require.NoError(t, err)
+	require.Equal(t, uint64(1), rRes.ObjectsMoved)
+	require.Equal(t, uint64(0), rRes.FilesRemoved)
+
+	require.NoError(t, b.Close())
+
+	blz := blobovnicza.New(blobovnicza.WithPath(filepath.Join(dir, "0", "0", "1.db")))
+	require.NoError(t, blz.Open())
+	require.NoError(t, blz.Init())
+
+	moveInfo, err := blz.ListMoveInfo(context.Background())
+	require.NoError(t, err)
+	require.Equal(t, 0, len(moveInfo))
+
+	var gPrm blobovnicza.GetPrm
+	gPrm.SetAddress(object.AddressOf(obj))
+	_, err = blz.Get(context.Background(), gPrm)
+	require.True(t, client.IsErrObjectNotFound(err))
+
+	require.NoError(t, blz.Close())
+
+	blz = blobovnicza.New(blobovnicza.WithPath(filepath.Join(dir, "0", "0", "0.db")))
+	require.NoError(t, blz.Open())
+	require.NoError(t, blz.Init())
+
+	moveInfo, err = blz.ListMoveInfo(context.Background())
+	require.NoError(t, err)
+	require.Equal(t, 0, len(moveInfo))
+
+	gRes, err := blz.Get(context.Background(), gPrm)
+	require.NoError(t, err)
+	require.True(t, len(gRes.Object()) > 0)
+
+	if mustUpdateStorageID {
+		require.True(t, bytes.Equal([]byte("0/0/0"), metaStub.storageIDs[object.AddressOf(obj)]))
+	}
+
+	require.NoError(t, blz.Close())
+}

pkg/local_object_storage/blobstor/blobovniczatree/rebuild_test.go

@@ -0,0 +1,145 @@
+package blobovniczatree
+
+import (
+	"context"
+	"sync"
+	"testing"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/internal/blobstortest"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger/test"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/sync/errgroup"
+)
+
+func TestBlobovniczaTreeRebuild(t *testing.T) {
+	t.Parallel()
+
+	t.Run("width increased", func(t *testing.T) {
+		t.Parallel()
+		testBlobovniczaTreeRebuildHelper(t, 2, 2, 2, 3, false)
+	})
+
+	t.Run("width reduced", func(t *testing.T) {
+		t.Parallel()
+		testBlobovniczaTreeRebuildHelper(t, 2, 2, 2, 1, true)
+	})
+
+	t.Run("depth increased", func(t *testing.T) {
+		t.Parallel()
+		testBlobovniczaTreeRebuildHelper(t, 1, 2, 2, 2, true)
+	})
+
+	t.Run("depth reduced", func(t *testing.T) {
+		t.Parallel()
+		testBlobovniczaTreeRebuildHelper(t, 2, 2, 1, 2, true)
+	})
+}
+
+func testBlobovniczaTreeRebuildHelper(t *testing.T, sourceDepth, sourceWidth, targetDepth, targetWidth uint64, shouldMigrate bool) {
+	dir := t.TempDir()
+	b := NewBlobovniczaTree(
+		WithLogger(test.NewLogger(t, true)),
+		WithObjectSizeLimit(2048),
+		WithBlobovniczaShallowWidth(sourceWidth),
+		WithBlobovniczaShallowDepth(sourceDepth),
+		WithRootPath(dir),
+		WithBlobovniczaSize(100*1024*1024),
+		WithWaitBeforeDropDB(0),
+		WithOpenedCacheSize(1000),
+		WithMoveBatchSize(3))
+	require.NoError(t, b.Open(false))
+	require.NoError(t, b.Init())
+
+	eg, egCtx := errgroup.WithContext(context.Background())
+	storageIDs := make(map[oid.Address][]byte)
+	storageIDsGuard := &sync.Mutex{}
+	for i := 0; i < 1000; i++ {
+		eg.Go(func() error {
+			obj := blobstortest.NewObject(1024)
+			data, err := obj.Marshal()
+			if err != nil {
+				return err
+			}
+			var prm common.PutPrm
+			prm.Address = object.AddressOf(obj)
+			prm.RawData = data
+			res, err := b.Put(egCtx, prm)
+			if err != nil {
+				return err
+			}
+			storageIDsGuard.Lock()
+			storageIDs[prm.Address] = res.StorageID
+			storageIDsGuard.Unlock()
+			return nil
+		})
+	}
+
+	require.NoError(t, eg.Wait())
+	require.NoError(t, b.Close())
+
+	b = NewBlobovniczaTree(
+		WithLogger(test.NewLogger(t, true)),
+		WithObjectSizeLimit(2048),
+		WithBlobovniczaShallowWidth(targetWidth),
+		WithBlobovniczaShallowDepth(targetDepth),
+		WithRootPath(dir),
+		WithBlobovniczaSize(100*1024*1024),
+		WithWaitBeforeDropDB(0),
+		WithOpenedCacheSize(1000),
+		WithMoveBatchSize(3))
+	require.NoError(t, b.Open(false))
+	require.NoError(t, b.Init())
+
+	for addr, storageID := range storageIDs {
+		var gPrm common.GetPrm
+		gPrm.Address = addr
+		gPrm.StorageID = storageID
+		_, err := b.Get(context.Background(), gPrm)
+		require.NoError(t, err)
+	}
+
+	metaStub := &storageIDUpdateStub{
+		storageIDs: storageIDs,
+		guard:      &sync.Mutex{},
+	}
+	var rPrm common.RebuildPrm
+	rPrm.MetaStorage = metaStub
+	rPrm.WorkerLimiter = &rebuildLimiterStub{}
+	rRes, err := b.Rebuild(context.Background(), rPrm)
+	require.NoError(t, err)
+	dataMigrated := rRes.ObjectsMoved > 0 || rRes.FilesRemoved > 0 || metaStub.updatedCount > 0
+	require.Equal(t, shouldMigrate, dataMigrated)
+
+	for addr, storageID := range storageIDs {
+		var gPrm common.GetPrm
+		gPrm.Address = addr
+		gPrm.StorageID = storageID
+		_, err := b.Get(context.Background(), gPrm)
+		require.NoError(t, err)
+	}
+
+	require.NoError(t, b.Close())
+}
+
+type storageIDUpdateStub struct {
+	guard        *sync.Mutex
+	storageIDs   map[oid.Address][]byte
+	updatedCount uint64
+}
+
+func (s *storageIDUpdateStub) UpdateStorageID(ctx context.Context, addr oid.Address, storageID []byte) error {
+	s.guard.Lock()
+	defer s.guard.Unlock()
+
+	s.storageIDs[addr] = storageID
+	s.updatedCount++
+	return nil
+}
+
+type rebuildLimiterStub struct{}
+
+func (s *rebuildLimiterStub) AcquireWorkSlot(context.Context) error { return nil }
+func (s *rebuildLimiterStub) ReleaseWorkSlot()                      {}

pkg/local_object_storage/blobstor/common/rebuild.go

@@ -0,0 +1,26 @@
+package common
+
+import (
+	"context"
+
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+)
+
+type RebuildRes struct {
+	ObjectsMoved uint64
+	FilesRemoved uint64
+}
+
+type RebuildPrm struct {
+	MetaStorage   MetaStorage
+	WorkerLimiter ConcurrentWorkersLimiter
+}
+
+type MetaStorage interface {
+	UpdateStorageID(ctx context.Context, addr oid.Address, storageID []byte) error
+}
+
+type ConcurrentWorkersLimiter interface {
+	AcquireWorkSlot(ctx context.Context) error
+	ReleaseWorkSlot()
+}

pkg/local_object_storage/blobstor/common/storage.go

@@ -30,4 +30,5 @@ type Storage interface {
 	Put(context.Context, PutPrm) (PutRes, error)
 	Delete(context.Context, DeletePrm) (DeleteRes, error)
 	Iterate(context.Context, IteratePrm) (IterateRes, error)
+	Rebuild(context.Context, RebuildPrm) (RebuildRes, error)
 }

pkg/local_object_storage/blobstor/fstree/fstree.go

@@ -574,3 +574,7 @@ func (t *FSTree) SetReportErrorFunc(_ func(string, error)) {
 func (t *FSTree) SetParentID(parentID string) {
 	t.metrics.SetParentID(parentID)
 }
+
+func (t *FSTree) Rebuild(_ context.Context, _ common.RebuildPrm) (common.RebuildRes, error) {
+	return common.RebuildRes{}, nil
+}

pkg/local_object_storage/blobstor/memstore/memstore.go

@@ -159,3 +159,7 @@ func (s *memstoreImpl) Iterate(_ context.Context, req common.IteratePrm) (common
 	}
 	return common.IterateRes{}, nil
 }
+
+func (s *memstoreImpl) Rebuild(_ context.Context, _ common.RebuildPrm) (common.RebuildRes, error) {
+	return common.RebuildRes{}, nil
+}

pkg/local_object_storage/blobstor/rebuild.go

@@ -0,0 +1,45 @@
+package blobstor
+
+import (
+	"context"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"go.uber.org/zap"
+)
+
+type StorageIDUpdate interface {
+	UpdateStorageID(ctx context.Context, addr oid.Address, storageID []byte) error
+}
+
+type ConcurrentWorkersLimiter interface {
+	AcquireWorkSlot(ctx context.Context) error
+	ReleaseWorkSlot()
+}
+
+func (b *BlobStor) Rebuild(ctx context.Context, upd StorageIDUpdate, limiter ConcurrentWorkersLimiter) error {
+	var summary common.RebuildRes
+	var rErr error
+	for _, storage := range b.storage {
+		res, err := storage.Storage.Rebuild(ctx, common.RebuildPrm{
+			MetaStorage:   upd,
+			WorkerLimiter: limiter,
+		})
+		summary.FilesRemoved += res.FilesRemoved
+		summary.ObjectsMoved += res.ObjectsMoved
+		if err != nil {
+			b.log.Error(logs.BlobstorRebuildFailedToRebuildStorages,
+				zap.String("failed_storage_path", storage.Storage.Path()),
+				zap.String("failed_storage_type", storage.Storage.Type()),
+				zap.Error(err))
+			rErr = err
+			break
+		}
+	}
+	b.log.Info(logs.BlobstorRebuildRebuildStoragesCompleted,
+		zap.Bool("success", rErr == nil),
+		zap.Uint64("total_files_removed", summary.FilesRemoved),
+		zap.Uint64("total_objects_moved", summary.ObjectsMoved))
+	return rErr
+}

pkg/local_object_storage/blobstor/teststore/teststore.go

@@ -229,3 +229,7 @@ func (s *TestStore) Iterate(ctx context.Context, req common.IteratePrm) (common.
 }
 
 func (s *TestStore) SetParentID(string) {}
+
+func (s *TestStore) Rebuild(_ context.Context, _ common.RebuildPrm) (common.RebuildRes, error) {
+	return common.RebuildRes{}, nil
+}

pkg/local_object_storage/engine/engine.go

@@ -38,6 +38,7 @@ type StorageEngine struct {
 		err error
 	}
 	evacuateLimiter *evacuationLimiter
+	rebuildLimiter  *rebuildLimiter
 }
 
 type shardWrapper struct {
@@ -215,13 +216,15 @@ type cfg struct {
 	shardPoolSize uint32
 
 	lowMem bool
+
+	rebuildWorkersCount uint32
 }
 
 func defaultCfg() *cfg {
 	return &cfg{
-		log: &logger.Logger{Logger: zap.L()},
+		log:                 &logger.Logger{Logger: zap.L()},
-
+		shardPoolSize:       20,
-		shardPoolSize: 20,
+		rebuildWorkersCount: 100,
 	}
 }
 
@@ -240,6 +243,7 @@ func New(opts ...Option) *StorageEngine {
 		closeCh:         make(chan struct{}),
 		setModeCh:       make(chan setModeRequest),
 		evacuateLimiter: &evacuationLimiter{},
+		rebuildLimiter:  newRebuildLimiter(c.rebuildWorkersCount),
 	}
 }
 
@@ -277,3 +281,10 @@ func WithLowMemoryConsumption(lowMemCons bool) Option {
 		c.lowMem = lowMemCons
 	}
 }
+
+// WithRebuildWorkersCount returns an option to set the count of concurrent rebuild workers.
+func WithRebuildWorkersCount(count uint32) Option {
+	return func(c *cfg) {
+		c.rebuildWorkersCount = count
+	}
+}

pkg/local_object_storage/engine/rebuild_limiter.go

@@ -0,0 +1,26 @@
+package engine
+
+import "context"
+
+type rebuildLimiter struct {
+	semaphore chan struct{}
+}
+
+func newRebuildLimiter(workersCount uint32) *rebuildLimiter {
+	return &rebuildLimiter{
+		semaphore: make(chan struct{}, workersCount),
+	}
+}
+
+func (l *rebuildLimiter) AcquireWorkSlot(ctx context.Context) error {
+	select {
+	case l.semaphore <- struct{}{}:
+		return nil
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+}
+
+func (l *rebuildLimiter) ReleaseWorkSlot() {
+	<-l.semaphore
+}

pkg/local_object_storage/engine/shards.go

@@ -118,6 +118,7 @@ func (e *StorageEngine) createShard(ctx context.Context, opts []shard.Option) (*
 		shard.WithExpiredLocksCallback(e.processExpiredLocks),
 		shard.WithDeletedLockCallback(e.processDeletedLocks),
 		shard.WithReportErrorFunc(e.reportShardErrorBackground),
+		shard.WithRebuildWorkerLimiter(e.rebuildLimiter),
 	)...)
 
 	if err := sh.UpdateID(ctx); err != nil {

pkg/local_object_storage/metrics/blobovnicza.go

@@ -42,6 +42,18 @@ func (m *blobovniczaTreeMetrics) Close() {
 	m.m.CloseBlobobvnizcaTree(m.shardID, m.path)
 }
 
+func (m *blobovniczaTreeMetrics) SetRebuildStatus(status string) {
+	m.m.BlobovniczaTreeRebuildStatus(m.shardID, m.path, status)
+}
+
+func (m *blobovniczaTreeMetrics) SetRebuildPercent(value uint32) {
+	m.m.BlobovniczaTreeRebuildPercent(m.shardID, m.path, value)
+}
+
+func (m *blobovniczaTreeMetrics) ObjectMoved(d time.Duration) {
+	m.m.BlobovniczaTreeObjectMoved(m.shardID, m.path, d)
+}
+
 func (m *blobovniczaTreeMetrics) Delete(d time.Duration, success, withStorageID bool) {
 	m.m.BlobobvnizcaTreeMethodDuration(m.shardID, m.path, "Delete", d, success, metrics_impl.NullBool{Valid: true, Bool: withStorageID})
 }

pkg/local_object_storage/shard/control.go

@@ -162,6 +162,9 @@ func (s *Shard) Init(ctx context.Context) error {
 
 	s.gc.init(ctx)
 
+	s.rb = newRebuilder(s.rebuildLimiter)
+	s.rb.Start(ctx, s.blobStor, s.metaBase, s.log)
+
 	return nil
 }
 
@@ -266,6 +269,9 @@ func (s *Shard) refillTombstoneObject(ctx context.Context, obj *objectSDK.Object
 
 // Close releases all Shard's components.
 func (s *Shard) Close() error {
+	if s.rb != nil {
+		s.rb.Stop(s.log)
+	}
 	components := []interface{ Close() error }{}
 
 	if s.pilorama != nil {
@@ -310,6 +316,11 @@ func (s *Shard) Reload(ctx context.Context, opts ...Option) error {
 	unlock := s.lockExclusive()
 	defer unlock()
 
+	s.rb.Stop(s.log)
+	defer func() {
+		s.rb.Start(ctx, s.blobStor, s.metaBase, s.log)
+	}()
+
 	ok, err := s.metaBase.Reload(c.metaOpts...)
 	if err != nil {
 		if errors.Is(err, meta.ErrDegradedMode) {

pkg/local_object_storage/shard/rebuild_limiter.go

@@ -0,0 +1,13 @@
+package shard
+
+import "context"
+
+type RebuildWorkerLimiter interface {
+	AcquireWorkSlot(ctx context.Context) error
+	ReleaseWorkSlot()
+}
+
+type noopRebuildLimiter struct{}
+
+func (l *noopRebuildLimiter) AcquireWorkSlot(context.Context) error { return nil }
+func (l *noopRebuildLimiter) ReleaseWorkSlot()                      {}

pkg/local_object_storage/shard/rebuilder.go

@@ -0,0 +1,98 @@
+package shard
+
+import (
+	"context"
+	"errors"
+	"sync"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor"
+	meta "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/metabase"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+	"go.uber.org/zap"
+)
+
+type rebuilder struct {
+	mtx     *sync.Mutex
+	wg      *sync.WaitGroup
+	cancel  func()
+	limiter RebuildWorkerLimiter
+}
+
+func newRebuilder(l RebuildWorkerLimiter) *rebuilder {
+	return &rebuilder{
+		mtx:     &sync.Mutex{},
+		wg:      &sync.WaitGroup{},
+		cancel:  nil,
+		limiter: l,
+	}
+}
+
+func (r *rebuilder) Start(ctx context.Context, bs *blobstor.BlobStor, mb *meta.DB, log *logger.Logger) {
+	r.mtx.Lock()
+	defer r.mtx.Unlock()
+
+	r.start(ctx, bs, mb, log)
+}
+
+func (r *rebuilder) start(ctx context.Context, bs *blobstor.BlobStor, mb *meta.DB, log *logger.Logger) {
+	if r.cancel != nil {
+		r.stop(log)
+	}
+	ctx, cancel := context.WithCancel(ctx)
+	r.cancel = cancel
+	r.wg.Add(1)
+	go func() {
+		defer r.wg.Done()
+
+		log.Info(logs.BlobstoreRebuildStarted)
+		if err := bs.Rebuild(ctx, &mbStorageIDUpdate{mb: mb}, r.limiter); err != nil {
+			log.Warn(logs.FailedToRebuildBlobstore, zap.Error(err))
+		} else {
+			log.Info(logs.BlobstoreRebuildCompletedSuccessfully)
+		}
+	}()
+}
+
+func (r *rebuilder) Stop(log *logger.Logger) {
+	r.mtx.Lock()
+	defer r.mtx.Unlock()
+
+	r.stop(log)
+}
+
+func (r *rebuilder) stop(log *logger.Logger) {
+	if r.cancel == nil {
+		return
+	}
+
+	r.cancel()
+	r.wg.Wait()
+	r.cancel = nil
+	log.Info(logs.BlobstoreRebuildStopped)
+}
+
+var errMBIsNotAvailable = errors.New("metabase is not available")
+
+type mbStorageIDUpdate struct {
+	mb *meta.DB
+}
+
+func (u *mbStorageIDUpdate) UpdateStorageID(ctx context.Context, addr oid.Address, storageID []byte) error {
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+	}
+
+	if u.mb == nil {
+		return errMBIsNotAvailable
+	}
+
+	var prm meta.UpdateStorageIDPrm
+	prm.SetAddress(addr)
+	prm.SetStorageID(storageID)
+	_, err := u.mb.UpdateStorageID(ctx, prm)
+	return err
+}

pkg/local_object_storage/shard/shard.go

@@ -39,6 +39,8 @@ type Shard struct {
 
 	tsSource TombstoneSource
 
+	rb *rebuilder
+
 	gcCancel         atomic.Value
 	setModeRequested atomic.Bool
 }
@@ -125,6 +127,8 @@ type cfg struct {
 	metricsWriter MetricsWriter
 
 	reportErrorFunc func(selfID string, message string, err error)
+
+	rebuildLimiter RebuildWorkerLimiter
 }
 
 func defaultCfg() *cfg {
@@ -133,6 +137,7 @@ func defaultCfg() *cfg {
 		log:             &logger.Logger{Logger: zap.L()},
 		gcCfg:           defaultGCCfg(),
 		reportErrorFunc: func(string, string, error) {},
+		rebuildLimiter:  &noopRebuildLimiter{},
 	}
 }
 
@@ -370,6 +375,14 @@ func WithExpiredCollectorWorkerCount(count int) Option {
 	}
 }
 
+// WithRebuildWorkerLimiter return option to set concurrent
+// workers count of storage rebuild operation.
+func WithRebuildWorkerLimiter(l RebuildWorkerLimiter) Option {
+	return func(c *cfg) {
+		c.rebuildLimiter = l
+	}
+}
+
 func (s *Shard) fillInfo() {
 	s.cfg.info.MetaBaseInfo = s.metaBase.DumpInfo()
 	s.cfg.info.BlobStorInfo = s.blobStor.DumpInfo()

pkg/metrics/blobovnicza.go

@@ -23,16 +23,23 @@ type BlobobvnizcaMetrics interface {
 
 	IncOpenBlobovniczaCount(shardID, path string)
 	DecOpenBlobovniczaCount(shardID, path string)
+
+	BlobovniczaTreeRebuildStatus(shardID, path, status string)
+	BlobovniczaTreeRebuildPercent(shardID, path string, value uint32)
+	BlobovniczaTreeObjectMoved(shardID, path string, d time.Duration)
 }
 
 type blobovnicza struct {
-	treeMode        *shardIDPathModeValue
+	treeMode               *shardIDPathModeValue
-	treeReqDuration *prometheus.HistogramVec
+	treeReqDuration        *prometheus.HistogramVec
-	treePut         *prometheus.CounterVec
+	treePut                *prometheus.CounterVec
-	treeGet         *prometheus.CounterVec
+	treeGet                *prometheus.CounterVec
-	treeOpenSize    *prometheus.GaugeVec
+	treeOpenSize           *prometheus.GaugeVec
-	treeOpenItems   *prometheus.GaugeVec
+	treeOpenItems          *prometheus.GaugeVec
-	treeOpenCounter *prometheus.GaugeVec
+	treeOpenCounter        *prometheus.GaugeVec
+	treeObjectMoveDuration *prometheus.HistogramVec
+	treeRebuildStatus      *shardIDPathModeValue
+	treeRebuildPercent     *prometheus.GaugeVec
 }
 
 func newBlobovnicza() *blobovnicza {
@@ -75,6 +82,19 @@ func newBlobovnicza() *blobovnicza {
 			Name:      "open_blobovnicza_count",
 			Help:      "Count of opened blobovniczas of Blobovnicza tree",
 		}, []string{shardIDLabel, pathLabel}),
+		treeObjectMoveDuration: metrics.NewHistogramVec(prometheus.HistogramOpts{
+			Namespace: namespace,
+			Subsystem: blobovniczaTreeSubSystem,
+			Name:      "object_move_duration_seconds",
+			Help:      "Accumulated Blobovnicza tree object move duration",
+		}, []string{shardIDLabel, pathLabel}),
+		treeRebuildStatus: newShardIDPathMode(blobovniczaTreeSubSystem, "rebuild_status", "Blobovnicza tree rebuild status"),
+		treeRebuildPercent: metrics.NewGaugeVec(prometheus.GaugeOpts{
+			Namespace: namespace,
+			Subsystem: blobovniczaTreeSubSystem,
+			Name:      "rebuild_complete_percent",
+			Help:      "Percent of rebuild completeness",
+		}, []string{shardIDLabel, pathLabel}),
 	}
 }
 
@@ -96,6 +116,15 @@ func (b *blobovnicza) CloseBlobobvnizcaTree(shardID, path string) {
 		shardIDLabel: shardID,
 		pathLabel:    path,
 	})
+	b.treeObjectMoveDuration.DeletePartialMatch(prometheus.Labels{
+		shardIDLabel: shardID,
+		pathLabel:    path,
+	})
+	b.treeRebuildPercent.DeletePartialMatch(prometheus.Labels{
+		shardIDLabel: shardID,
+		pathLabel:    path,
+	})
+	b.treeRebuildStatus.SetMode(shardID, path, undefinedStatus)
 }
 
 func (b *blobovnicza) BlobobvnizcaTreeMethodDuration(shardID, path string, method string, d time.Duration, success bool, withStorageID NullBool) {
@@ -163,3 +192,21 @@ func (b *blobovnicza) SubOpenBlobovniczaItems(shardID, path string, items uint64
 		pathLabel:    path,
 	}).Sub(float64(items))
 }
+
+func (b *blobovnicza) BlobovniczaTreeRebuildStatus(shardID, path, status string) {
+	b.treeRebuildStatus.SetMode(shardID, path, status)
+}
+
+func (b *blobovnicza) BlobovniczaTreeObjectMoved(shardID, path string, d time.Duration) {
+	b.treeObjectMoveDuration.With(prometheus.Labels{
+		shardIDLabel: shardID,
+		pathLabel:    path,
+	}).Observe(d.Seconds())
+}
+
+func (b *blobovnicza) BlobovniczaTreeRebuildPercent(shardID, path string, value uint32) {
+	b.treeRebuildPercent.With(prometheus.Labels{
+		shardIDLabel: shardID,
+		pathLabel:    path,
+	}).Set(float64(value))
+}

pkg/metrics/consts.go

@@ -45,4 +45,5 @@ const (
 
 	failedToDeleteStatus = "failed_to_delete"
 	deletedStatus        = "deleted"
+	undefinedStatus      = "undefined"
 )