Hi, last Sunday I experienced a power outage with one of my two oVirt hypervisors. After power was restored I experienced some weirdness: - on one of the VMs running on this hypervisor the boot disk changed, so it was no longer able to boot. Looking at the console the VM would hang on "Booting from hard disk". After I noticed that the wrong virtual disk was marked as OS/bootable I got it booting again after correcting it to the proper boot disk. This was done from the oVirt management server. - on another VM I tried today to add another virtual disk to expand a LVM volume. In dmesg I can see the new device: [17167560.005768] vdc: unknown partition table However, when I tried to run pvcreate I got an error message saying that this was already marked as an LVM disk, and then running pvs give me the following error: # pvs Couldn't find device with uuid 7dDcyq-TZ6I-96Im-lfjL-cTUv-nff1-B11Mm7. PV VG Fmt Attr PSize PFree /dev/vda5 rit-kvm-ssweb02 lvm2 a-- 59.76g 0 /dev/vdb1 vg_syncshare lvm2 a-- 500.00g 0 /dev/vdc1 VG_SYNCSHARE01 lvm2 a-- 400.00g 0 unknown device VG_SYNCSHARE01 lvm2 a-m 1024.00g 0 As you can see there's already a PV called /dev/vdc1, as well another one named "unknown device". These two PVs belong to a VG that does NOT belong to this VM, VG_SYNCSHARE01. The uuids for these two PVs are: --- Physical volume --- PV Name unknown device VG Name VG_SYNCSHARE01 PV Size 1024.00 GiB / not usable 3.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 262143 Free PE 0 Allocated PE 262143 PV UUID 7dDcyq-TZ6I-96Im-lfjL-cTUv-nff1-B11Mm7 --- Physical volume --- PV Name /dev/vdc1 VG Name VG_SYNCSHARE01 PV Size 400.00 GiB / not usable 3.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 102399 Free PE 0 Allocated PE 102399 PV UUID oKSDoo-3pxU-0uue-zQ0H-kv1N-lyPa-P2M2FY The two PVs which doesn't belong on this VM actually belongs to a totally different VM. On VM number two: # pvdisplay --- Physical volume --- PV Name /dev/vdb1 VG Name VG_SYNCSHARE01 PV Size 1024.00 GiB / not usable 3.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 262143 Free PE 0 Allocated PE 262143 PV UUID 7dDcyq-TZ6I-96Im-lfjL-cTUv-nff1-B11Mm7 --- Physical volume --- PV Name /dev/vdd1 VG Name VG_SYNCSHARE01 PV Size 400.00 GiB / not usable 3.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 102399 Free PE 0 Allocated PE 102399 PV UUID oKSDoo-3pxU-0uue-zQ0H-kv1N-lyPa-P2M2FY As you can see, same uuid and VG name, but two different VMs. My setup: oVirt manager: oVirt 3.5 running on CentOS 6.7 oVirt hypervisors: two oVirt 3.5 servers running on CentOS 6.7 During the time of the power outage mentioned earlier I was running oVirt 3.4, but I upgraded today and rebooted the manager and both hypervisors, but NOT the VMs. Virtual machines: Debian wheezy 7.9 x86_64 Storage: HP LeftHand iSCSI I have tried to locate error messages in the logs which can be related to this behaviour, but so far no luck :( -- Morten A. Middelthon Email: morten(a)flipp.net