Another Calendar-based Tarsnap Script

acts is a minimal shell script that creates backups with Tarsnap. Some design goals:

• Just backup, no restore.
• Calendar-based (daily, monthly, yearly) backup schedule
• Portable, small code footprint.

One Tarsnap archive is created per-target per-run. 31 daily, 12 monthly, and indefinite yearly backups are kept.

1. Take acts.conf and customise it for your environment. Put it in /etc.
2. Run acts daily from cron.

Notes on behaviour:

• acts creates archives of the form <hostname>-<period>-yyyy-mm-dd_HH:MM:SS-target. If you have existing archives starting with hostname-(daily|monthly|yearly), they will confuse acts, so don't do that.
• Archives are created using the following logic:
  • If no yearly backup for the current year exists, create a yearly backup.
  • If a yearly backup exists but no monthly backup, create a monthly backup.
  • Otherwise, create a daily backup.
• Archives are deleted using the following logic:
  • If any backups failed, delete nothing.
  • Keep the most recent 31 daily backups, and delete any older ones.
  • Keep the most recent 12 monthly backups, and delete any older ones.
  • Do not delete any yearly backups.
• Times in archive names use UTC, not the server's timezone.

• Add per-directory excludes handling. (For now, add global excludes in your tarsnap.conf or .tarsnaprc file.)
• Add some backup period configurability. (For now, you can edit the hardcoded values in the script.)

Email me ([email protected]) or open a Github issue.