Citrix XenServer virtual machines

This section provides details and requirements for protecting Citrix XenServer environments with host-level backups.

When you add a XenServer host to the Unitrends appliance, its VMs are discovered and available for host-level protection. Following is a summary of the high-level steps that protect XenServer virtual machines. Included are links to detailed instructions for each procedure.

1 Review the Best practices and requirements for XenServer protection.
2 Add the XenServer host to your Unitrends appliance. See Adding a virtual host.
3 Create backup jobs for your VMs. See Creating backup jobs.

Review the information in these topics before implementing XenServer host-level protection:

Host-level protection of XenServer VMs is supported on Unitrends Backup on Citrix XenServer appliances only.

Note:  To protect XenServer VMs using other Unitrends appliance types, use agent-based backups instead. For details, see File-level Backups Overview.

The XenServer host must be running a licensed version listed in the Unitrends Compatibility and Interoperability Matrix. The host must be one of the following:

• A XenServer pool master host meeting both of these criteria:
– The Unitrends Backup VM resides either on the pool master host itself or on one of the pool master's slave hosts.
– The Unitrends Backup VM has been granted access to the shared storage used by the pool master host.
• A stand-alone XenServer host where the Unitrends Backup VM resides.

Only one XenServer host can be added to the Unitrends Backup appliance. (See the procedure To add a virtual host asset.) See the following for considerations by host type:

Host type

Description
XenServer pool master host
• By adding the pool master host to the Unitrends Backup appliance, you can protect the following:
– VMs on the host where the Unitrends Backup VM resides. This can be the pool master host itself or one of the pool master's slave hosts.
– VMs that reside on shared storage in the resource pool.
• While adding the pool master host to the Unitrends Backup appliance, enter its username and password credentials in the Add Virtual Host dialog. These credentials are needed because the XenServer APIs have to communicate via the pool master. The appliance can then discover hosted VMs and VM slaves, as well as track any VM changes.

Stand-alone XenServer host
• By adding the XenServer host to the appliance, you can protect its hosted VMs.
• While adding the XenServer host to the Unitrends Backup appliance, enter its username and password credentials in the Add Virtual Host dialog.

Follow these best practices to protect your XenServer virtual machines:

• Adhere to all Citrix XenServer best practices. This information can be found in your Citrix XenServer Administrator's guide.

Note:  Failure to comply with Citrix recommendations for quiesced snapshots can result in backup failures.

• If you are deploying multiple Unitrends Backup appliances in your XenServer environment, be sure to back up each VM from one appliance only. This ensures that a given VM will not be backed up simultaneously by multiple appliances, which can cause undesirable results.
• Backups can protect VMs, VMs on slave XenServer hosts, and user-configured templates. Only full backups are supported.
• To back up VM disks, the Unitrends Backup appliance must have access to the storage repositories where the disks reside. If the appliance cannot access any VM disk, the backup fails.
• In some cases, you may want or need to protect VMs using file-level backups. If you choose to protect a VM with both host-level and file-level (agent-based) backups, ensure that the VM's host-level and file-level jobs do not overlap. Running both simultaneously may lead to undesirable results.