XenServer offers a range of features to enable you to protect your VMs and vApps.
High Availability (HA)
XenServer High Availability (HA) provides protection against downtime of critical VMs caused by the failure of individual servers in a pool by guaranteeing that VMs are automatically restarted on an alternate server in the same pool, with minimal service interruption. The pool database is constantly replicated across all nodes and is also backed up to shared storage on the heartbeat SR for additional safety.
Read more: About XenServer HA; HA requirements; VM startup settings; Configure HA; Disable HA; Change HA settings
Disaster Recovery (DR)
XenServer Disaster Recovery (DR) provides protection against the loss of multiple servers at your primary data site. With DR enabled, the pool database is constantly replicated via mirrored storage, and in the event of a disaster at your primary site, VMs and vApps can be recovered from the mirrored storage to a pool on a secondary (DR) site.
Read more: About XenServer DR; Configuring DR; Failover; Failback; Test Failover