Reintegration of ZFS datastores after PBS reinstallation

This article describes how to reintegrate a consisting ZFS datastore after a reinstallation of the Proxmox Backup Server (PBS) without losing the safed backups.

Initial situation

In our setup, the PBS with configured ZFS is available. This article starts with the following initial situation:

• Proxmox Backup Server (Version 4.0.11)
• configured datastore (ZFS in this case)

Before starting the next steps, the PBS must be reinstalled. You will find instructions for this here: Proxmox Backup Server Installation.

Target

Reintegrate the ZFS datastore into the PBS without losing the safed backups.

Performance

Verification of hard disks

After you have reinstalled your Proxmox Backup server, you have to check first if your data carrier is displayed in the system:

lsblk

Importing ZFS pool

Next, the old zfs data stores are integrated in the new zpool. For this, perform the following steps.

Show all available ZFS pools:

zpool import

Import the desired old zfs data stores with the following command:

zpool import -f <POOLNAME>

The option -f forces the integration of the zpool.

Determining path of datastore

After this, the Mountpoint of the datastore is required. This can be viewed with the following command:

zfs list

The output can, for example, look as follows:

Note the mount point of the desired datastore. Here:

/mnt/datastore/pbs.local

This is required for the datastore configuration.

Configuration

Next, the PBS datastore configuration file is edited.

Hint: If no datastore has been configured after the reinstallation, the file is empty at the beginning and has to be created first.

nano /etc/proxmox-backup/datastore.cfg

Add new entry (Attention: Please note the formatting of the individual lines. It is best to copy the following codeblock and to adjust the names):

datastore: <Datastore-Name>
path <Mountpoint des ZFS-Pools>

Restart backup service

Finally, the backup service must be restarted:

systemctl restart proxmox-backup

After you have reloaded the GUI after starting the backup service, the datastore should now appear under "Datastore" with all available backups.

Now, you can add your Proxmox Backup server back to your Proxmox systems and adjust the datastore if necessary (Garbage Collection, Prune Jobs, etc.).

Translator: Alina Ranzinger Alina has been working at Thomas-Krenn.AG since 2024. After her training as multilingual business assistant, she got her job as assistant of the Product Management and is responsible for the translation of texts and for the organisation of the department.