Frequently asked questions

How do I decrypt an encrypted backup if I no longer use docker-backup?

First, install gnupg2 with sudo apt install gnupg2

Then decrypt it like this:

gpg2 --batch --passphrase "<PASSWORD>" -o <OUTPUT FILENAME> --decrypt <BACKUP NAME>

GnuPG will detect what algorithm was used for encryption, so you do not need to specify algorithm.

How do I verify a signature if I no longer use docker-backup?

First, install gnupg2 with sudo apt install gnupg2

Then import the signing_key.asc that you hopefully saved:

gpg2 --batch --import signing_key.asc

Now verify the .sig file:

gpg2 --verify <backup name>.sfv.sig <backup name>.sfv

The signatures are only a verification of the sfv checksum, so you need to have that file as well.

How do I verify a sfv checksum if I no longer use docker-backup?

First, install cksfv with sudo apt install cksfv

Then verify an sfv checksum like this:

cksfv -g <SFV FILENAME>

If it tells you Everything OK then the file is intact and valid.

My backups get the wrong timestamp. How do I change the timezone?

Use the TZ environment variable.

How do I keep permissions after restoring a backup?

To keep permissions, you need to set ARCHIVE_TYPE to tgz

Can I speed up the archiving of backups?

Backups are first written to /tmp/backup before moved to the backup folder. If you have enough memory to store your backups temporarily in memory before moving them to their final destination, you can mount a tmpfs in-memory filesystem at /tmp/backup to speed things up.

version: "3.7"

services:
  ...
  backup:
    ...
    tmpfs:
      - /tmp/backup:mode=700,uid=1000,gid=1000