Monitoring if zfs-autobackup succeeds
On completion, zfs-autobackup returns an exit code:
0: Everything went fine, no important errors.x: Snapshotting was ok, but there are x datasets that aborted with a fatal error.255: Wrong options or other major failure, probably nothing succeeded.
Output
Without --verbose or --debug, zfs-autobackup only echos (zfs) errors and warnings to stderr. Complete silence means everything is fine.
So if you stick it in a crontab it should only mail you if something is wrong.
If it detects a tty it will output progress updates to stdout.
Monitoring example with Zabbix-jobs
You can monitor backups by using my zabbix-jobs script. (https://github.com/psy0rz/stuff/tree/master/zabbix-jobs)
Put this command directly after the zfs_backup command in your cronjob:
This will update the zabbix server with the exit code and will also alert you if the job didn't run for more than 2 days.