Can't deactivate LV

[Simen Musaeus]

I'm running my VM from a iscsi-lvm san, and experience irregularly the following error when attempting to boot:

using uefi without permanent efivars disk
can't deactivate LV '/dev/rbvm/vm-1000-disk-1': Logical volume rbvm/vm-1000-disk-1 in use.
TASK ERROR: start failed: command '/usr/bin/kvm .....

What does it mean?