Craig Sanders <cas@taz.net.au> writes:
i was speculating that in the case of an mdadm raid array of iscsi zvols, it's possible the snapshots of the zvols on different servers could be different - it would be almost impossible to guarantee that the snapshots would run at exactly the same time.
Are you actually doing that? I once tried mdadm with remote drives, to see if it was a viable alternative to drbd. It fell over at the slightly transient network outage. Unless your network is invincible, I'm not sure this is a case worth thinking about.
if the VM is paused briefly, that would prevent the VM from writing to the raid array while it was being snapshotted.
Simply pausing the VM might not quiesce it -- it'd depend on whether a pause also implies a flush to disk. For example, lxc freeze basically just sends a SIGSTOP to all procs in the group.