Setup Guide

Best Practices 71
3 Take a snapshot of the SR and the Suspend SR (if different than the SR for
which the snapshot was created).
4 Power on the VMs on the primary XenServer host.
5 Attach the snapshot of the SR and Suspend SR (if different than the
SR for which the snapshot was created) on the secondary XenServer host.
6 Restore the VM metadata to recovery VMs.
7 Boot the VMs on the secondary XenServer host.
Snapshot a volume when VMs are running
In this scenario, a snapshot operation on an SR is initiated when the VM is in
a running state and performing I/O operations to the storage volume. Unlike
the scenarios described above, there is no service downtime. In LVM-based
SRs, taking a storage volume snapshot results in a file system and application
crash consistent snapshot. When you run an
iSCSI initiator inside the VM to
connect directly to SAN volumes, in which the I/O operations to virtual disks is
entirely controlled by the VM
, you can use array-based snapshots in
conjunction with frameworks such as Microsoft VSS or VDS to create
application-consistent snapshots. This approach is useful when each virtual
disk of a VM is a separate volume on storage array.
Backup the VM Metadata
This section explains the steps required to backup the VM metadata from the
primary XenServer host. This metadata can then be restored on the secondary
XenServer host where VMs need to be recovered.
1
Access the Backup, Update and Restore menu in the local console on the
XenServer host or pool master.
2 Trigger an immediate metadata backup to the SR being moved using the
Backup Virtual Machine Metadata menu option. The metadata backup
creates a backup virtual desktop infrastructure (VDI), if necessary, and
attaches it to the host, and then backs up all the metadata to that SR.