CLOUDSTACK-4459:
Libvirt reports:
org.libvirt.LibvirtException: Storage volume not found: no storage vol
with matching name
in some cases, if the volume is created on one kvm host, while accessed
from other host.
It's possible due to concurrent access(read/write) storage.
The current fix is to try serveral times, and wait for 30 seconds for
each retry.
If the issue still there, then need to sync the storage pool access
CLOUDSTACK-3237: add disk chain sync logic to handle out-of-band chain changes that could happen in storage live migration and VM snapshot operations