From b9b82d878d4f73ad4255cea09819153d2cce5d81 Mon Sep 17 00:00:00 2001 From: rawtaz <rawtaz@users.noreply.github.com> Date: Sat, 3 Oct 2020 13:27:21 +0200 Subject: [PATCH] Add FAQ on whether restic can resume backups This new FAQ entry explains that restic can resume interrupted backups. --- doc/faq.rst | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/doc/faq.rst b/doc/faq.rst index a93c4ed86..295f43966 100644 --- a/doc/faq.rst +++ b/doc/faq.rst @@ -3,6 +3,32 @@ FAQ This is the list of Frequently Asked Questions for restic. +Will restic resume an interrupted backup? +----------------------------------------- + +Yes, restic will resume interrupted backups when they are re-run. + +When backing up, restic periodically writes index files to keep a record of +the uploaded data. Even if there's no snapshot created in the end (due to the +backup being interrupted), these indexes are stored in the repository for the +data that has been uploaded so far. Next time restic runs, it is then able to +find the uploaded data through these indexes, and thereby reference it again +without having to upload it a second time. This effectively makes it continue +from where it saved the last index, which should be up to a few minutes ago. + +It does not matter if the backup was interrupted by the user or if it was due +to unforeseen circumstances such as connectivity issues, power loss, etc. +Simply re-run the backup again and restic should only upload what it needs to +in order to complete the interrupted backup and create a snapshot. + +Note however that during the initial backup run and any re-tries, until there +has been a first snapshot created for the backup set (list of files and +directories to be backed up), restic will need to re-scan the files on disk as +there is no parent snapshot to compare the filesystem with to determine which +files have changed. This process should however be far quicker than the +uploading, and it's normal to see restic scan the files again when re-running +the backup. + ``restic check`` reports packs that aren't referenced in any index, is my repository broken? --------------------------------------------------------------------------------------------