Back up the /etc/ceph directory. It contains crucial cluster configuration. You will need the backup of /etc/ceph for example when you need to replace the Admin Node.

You need to back up the /etc/salt/ directory. It contains the Salt configuration files, for example the Salt master key and accepted client keys.

The Salt files are not strictly required for backing up the Admin Node, but make redeploying the Salt cluster easier. If there is no backup of these files, the Salt minions need to be registered again at the new Admin Node.

Note: Security of the Salt Master Private Key

Make sure that the backup of the Salt master private key is stored in a safe location. The Salt master key can be used to manipulate all cluster nodes.

After restoring the /etc/salt directory from a backup, restart the Salt services:

root@master # systemctl restart salt-master
root@master # systemctl restart salt-minion

All files required by DeepSea are stored in /srv/pillar/, /srv/salt/ and /etc/salt/master.d.

If you need to redeploy the Admin Node, install the DeepSea package on the new node and move the backed up data back into the directories. DeepSea can then be used again without any further changes being required. Before using DeepSea again, make sure that all Salt minions are correctly registered on the Admin Node.