# zfs-snapshot-backup

**Automatically create (incremental) backups of zfs snapshots on a file server.**


This is currently tailored only to our setup of a FreeNAS in combination with
our virtual server and storage provided by the Rechenzentrum.

The script will create backups of ZFS snapshots for elab journals. The name of
the ZFS dataset (from wich the snapshots are created) must start with `elabfs-`
followed by the elab member name, e.g. `LukasMetzler`

The snapshots should be made with the `periodic snapshot task` provided by the
FreeNAS system. Snapshots should be kept on the NAS for a couple of days
(currently one week) to allow transfer errors not to interfere with the backup
process.

The backup process should be run after a snapshot is taken. Proposed is to take
a daily snapshot at night (currently between 2am and 3am) and start the backup
process later via cron (currently set to 4am).

The documentation in our wiki can be found at:
https://wiki.cpi.imtek.uni-freiburg.de/CPIvServerDocumentation/ElabOnZfs


## restoring backups ##

1. copy a snapshot backup to the NAS

    ```
    cd /mnt/Datenspeicher/snap-backup-dataset/temporary-backups/
    scp -i ../backup_key zfs_snap_backup@etha.cpi.imtek.uni-freiburg.de:~/zfs-backups/<backup-file> tmp-backup-file.gz
    ```

2. unzip the backup file and restore it into a dataset

    ```
    gunzip -c tmep-backup-file.gz | zfs receive -F Datenspeicher/test-backup
    ```

3. remove the (local) backup file

    ```
    rm tmp-backup-file.gz
    ```