ZFS Backup Script

Simple ZFS incremental backup to remote host script with retention and job reporting.

Installation

We use root user in this simple example. It is advisable to create a separate account with permission to use zfs tools to run this utility.

01. Setup access from backup source to backup target:

1. Create a new private key on backup source host: ssh-keygen -b 4096
2. Add source public key to target authorized_hosts.
3. Make sure that the user is able to connect target from source without entering password. In some systems you need to add PermitRootLogin without-password in sshd settings.

02. Install the utility

1. Clone the script repository from https://github.com/rennu/zfs-backup. In this example the repository was cloned to /opt/zfs-backup

2. Create a crontab job. In this example we backup filesystem tank/materials every 2nd hour to backup-host, keep 360 latest snapshots (30 days) and send a backup report to [email protected] 0 */2 * * * /usr/bin/python /opt/zfs-backup/zfs-backup.py --pool tank --filesystem materials --snapshots 360 --backuphost root@backup-server --email [email protected]

   Here are the used arguments listed:

   --pool tank Name of the pool to be backed up (tank)

   --filesystem materials Name of the filesystem to be backed up (materials)

   --snapshots 360 Keep 360 snapshots and automatically delete older ones

   --backuphost root@backup-server Username and host of the backup target host

   --email [email protected] Address where job reports are sent

Arguments

--pool [string]
    Pool to backup ie. tank

--targetpool [string] (optional)
    Pool name on the backup target host. If not set, --pool value will be used.

--backuphost [username@hostname]
    Backup target username and hostname

--filesystem [string] (optional)
    Filesystem to backup eg. materials. If not set, the whole --pool will be backed up

--snapshots [int] (optional)
    Number of snapshots to keep
    Default: 10

--email user@host;user2@host2 (optional)
    Send backup job reports to these email addresses. Separated by semicolon

--sender foo@bar
    Email address to use as sender address
    Default: zfsbackup@hostname

--smtp hostname (optional)
    SMTP server address
    Default: localhost

--only-errors
    Only send a job report if job has failed

--cipher
    Use ssh cipher other than system default. Some ciphers are fasther than others while some are less secure. You can list available ciphers by using ```ssh -Q cipher```. In the tests [email protected] was found to be performant.

--debug
    Output all commands

TODO

• Backup to local media ie. USB drive.
• Execute the script from backup target ie. backup systems that are outside company firewall.