configure guest virtual machines to use SAN storage using libvirt

Provision a new logical unit on iSCSI or fibre channel storage. Use virsh to trigger a scan for it, and confirm that it appears correctly.
To discover logical units on a particular HBA, create a pool for that HBA using:
virsh pool-create hbapool.xml
where hbapool.xml contains:

  host6
  /dev/disk/by-id
  

Confirm that all the appropriate logical units are visible as volumes with:
virsh vol-list host6
After creating the pool, add a new logical unit on a target that's visible on that host and refresh the pool with:
virsh pool-refresh host6
and confirm that the new storage is visible. Note that the refresh code only scans for new LUs on existing targets and does not issue a LIP to discover new targets as that would be disruptive to I/O.