On Mon, Feb 20, 2017 at 8:39 PM, Adam Litke <alitke(a)redhat.com> wrote:
Ok, thanks for clarifying that. So it looks like the temporary
snapshot
was already merged/deleted. As part of that operation, vdsm calculates how
large the original volume would have to be (LV size) in order to guarantee
that the base volume has enough space for the merge to complete. It looks
like in this case we decided that value was the virtual size + 10% for
qcow2 metadata. If your base volume was only about 16G allocated prior to
all of this than it seems we were way too conservative. Did you remove the
snapshot quickly after the move completed? One thing that could cause this
is if you wrote about 12-15 GB of data into the that disk after moving but
before deleting the temporary snapshot.
Do you happen to have the vdsm logs from the host running the VM and the
host that was acting SPM (if different) from during the time you
experienced this issue?
I executed some snapshot creation to test backup so with following live
merge after a couple of minutes without using that much VM in the mean time.
And I also tested storage migration.
I have not the logs but I can try to reproduce similar operations and then
send new log files if the anomaly persists...