Backing up metadata of pooled installations

In a pool scenario, the master host provides an authoritative database which is synchronously mirrored by all the slave hosts in the pool. This provides a degree of built-in redundancy to a pool; the master can be replaced by any slave since each of them has an accurate version of the pool database.

Please refer to the XenServer Administrator’s Guide for more information on how to transition a slave into becoming a master host.

This level of protection may not be sufficient; for example, if your shared storage containing the VM data is backed up in multiple sites, but your local server storage (containing the pool metadata) is not. 

To fully recreate a pool given just a set of shared storage, you must first backup the xe pool-dump-database against the master host, and archive this file.

# xe pool-dump database file-name= /raja/backups/my_backup

 To subsequently restore this backup on a brand new set of hosts

1. Install a fresh set of XenServer hosts from the installation media, or via PXE.
2. Use the xe pool-restore-database on the host designated to be the new master.
3. Run the xe host-forget command on the new master to remove the old slave machines.
4. Use the xe pool-join command on the slave hosts to connect them to the new cluster.

Note:

Removing a xenserver host from a pool will delete all the user data on local HDD of that host.