zsnapper - incremental zfs backups

Maybe it's not the best plan, but I'm making incremental backups of zfs datasets to removable USB storage.

Usage

Currently the script has TARGET=/mnt/backup as the target disk. Fix this if it's not quite right.

Start your first backup..

$ bash zsnapper.sh tank/home

The script will create a snapshot of the form tank/home@backup-9999-12-30 with today's date. Then, it will make a backup to /mnt/backup/tank/home/home@backup-9999-12-30.

Come back and run it again tomorrow, and it will create an incremental backup to /mnt/backup/tank/home/home@backup-9999-12-31 containing only the differences.

If you have multiple disks for /mnt/backup to swap in and out, it will check each one for the previous successful backup. That is, if /mnt/backup is a different disk and you re-run the script, it will build an incremental backup since the last time it was backed up to that disk.

Notes

• non-recursive. Only backs up one dataset at a time.

Bugs

Many. not enough error checking.

License and credits

• available under LICENSE, Apache-2.0

• thanks to @xai in https://xai.sh/2018/08/27/zfs-incremental-backups.html for the idea

• Author: Steven R. Loomis @srl295 of @codehivetx