Hello all,
i have a question regarding this note in ovirt storage documentation:
**Important:** If you are using block storage and you intend to deploy virtual machines on
raw devices or direct LUNs and to manage them with the Logical Volume Manager, you must
create a filter to hide the guest logical volumes. This will prevent guest logical volumes
from being activated when the host is booted, a situation that could lead to stale logical
volumes and cause data corruption.
What does "you must create a filter to hide the guest logical volumes" exactly
mean?
I assume i have to set some filter in lvm.conf on all ovirt hosts, but im not sure about
what to filter?
What i already saw is that after creating the ISCSI domain and cloning/moving/creating
virtual machines on it there are new PVs and LVs visible on the ovirt hosts having an
object UUID in the name (output from "pvs" and "lvs" commands).
Is this expected behavior or do i have to filter exactly this ones by allowing only local
disks to be scanned for PVs/LVs?
Or do i have to setup filter to allow only local disks + ISCSI disks (in my case /dev/sd?)
to be scanned for PVs/LVs?
I noticed too that after detaching and removing the ISCSI domain i still have UUID PVs.
They all show up with "input/output error" in the output of "pvs" and
stay there until i reboot the ovirt hosts.
On my ISCSI target system i already set the correct lvm filters so that
"targetcli" is happy after reboot.
Thank you!
Happy new year,
Robert