A pool is comprised of multiple XenServer host installations, bound together as a single managed entity. When combined with shared storage, a pool enables VMs to be started on any XenServer host in the pool that has sufficient memory and then dynamically move between hosts while running (XenMotion), with minimal downtime. If an individual XenServer host suffers a hardware failure, you can restart the failed VM(s) on another host in the same pool.
If the High Availability (HA) feature is enabled, protected VMs are automatically moved in the event of a host failure.
To set up shared storage between hosts in a pool, you need to create a storage repository. A XenServer storage repository (SR) is a storage container in which virtual disks are stored. SRs, like virtual disks, are persistent, ondisk objects that exist independently of XenServer. SRs can exist on different types of physical storage devices, both internal and external, including local disk devices...