We have 2 Servers with Citrix XEN 6.2. Both today suddenly both had troubles.
Both Server are Stand Alone with a Raid1 Disk for the System and a Raid5 Disk for the VM's.
It seems that both machines dropped the connection to the Raid5 Drive.
The Raid5 Disk is unplugged. When wie try pbd-plug [UUID] we get following error
Error code: SR_BACKEND_FAILURE_52
Error parameters: , Logical Volume mount/activate error [opterr=Unable to activa te LV. Errno is 5]
an fdisk -l tells us that there is no partition on the /dev/sdb device.
[root@hskxen02 ~]# fdisk -l
WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sda: 146.2 GB, 146263769088 bytes
256 heads, 63 sectors/track, 17712 cylinders
Units = cylinders of 16128 * 512 = 8257536 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 17713 142835711+ ee EFI GPT
Disk /dev/sdb: 1316.3 GB, 1316373921792 bytes
255 heads, 63 sectors/track, 160040 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdb doesn't contain a valid partition table