Keep all files with smart backup retention or not

Support
1

Hello. I am pretty new to duplicati and am not an IT-person.
I am not sure if all files that I backup with duplicati using smart backup retention, will be kept, also when I throw files away from my source. Or will they be lost after a certain time and should I choose for custom backup retention and set it up for Unlimited?

2

Hello @Kiepo, welcome to the forum!

I’m a little confused by the wording of your question, but it sounds like you’re asking what happens to files in your backup when they are delete from the source.

That depends on your retention settings as follows:

  • “Keep all backups” WILL keep files in the backup even if they’ve been deleted from the source forever. Note that to restore these files you’ll need to select a backup version from when the files still existed on the source.
  • “Delete backups that are older than” will keep files in the backup even after they’ve been deleted from the source but ONLY UNTIL the versions with those “deleted file” backups reach the “older than” time.
  • “Keep a specific number of backups” will keep files in the backup even after they’ve been deleted from the source but ONLY UNTIL the versions with those “deleted file” backups are higher than the specific number of backups.
  • “Smart backup retention” will keep files in the backup even after they’ve been deleted from the source but ONLY UNTIL the versions with those “deleted file” backups are more than 12 months old.
  • “Custom backup retention” MAY keep files in the backup even after they’ve been deleted from the source depending on your settings. For example, if you end your custom retention setting with “U:1Y” then you’ll forever have yearly versions of files (even if they’ve been deleted from the source)

BIG IMPORTANT NOTE!

When the retention policy cleanup happens, it basically deletes all versions of a backup that DON’T match up with the retention rules. This means that if your deleted file ONLY exists in one backup version and that backup HAPPENS to be one that is deleted during retention cleanup, then the file WILL be removed from the backup.

Other than the “Keep all backups” option, there is no guarantee that a deleted source file will be available in a backup version.

3

AFAIK this carries the important caveat that a deleted file would have to happen to be in the backup set that’s kept for the yearly record – since the smart/custom retention schemes work on a per-backup basis and not a per-file basis.

4

Thanks - post updated to (hopefully) point that out. :slight_smile:

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