Volume group disappeared, LVs still available
- by Ben
I've run into an issue with my KVM host which runs VMs on a LVM volume. As of last night the logical volumes are no longer seen as such (I can't create snapshots of them even though I have been for months now).
Running any scans all result in nothing being found:
[root@apollo ~]# pvscan
No matching physical volumes found
[root@apollo ~]# vgscan
Reading all physical volumes. This may take a while...
No volume groups found
root@apollo ~]# lvscan
No volume groups found
If I try restoring the VG conf backup from /etc/lvm/backups/vg0 I get the following error:
[root@apollo ~]# vgcfgrestore -f /etc/lvm/backup/vg0 vg0
Couldn't find device with uuid 20zG25-H8MU-UQPf-u0hD-NftW-ngsC-mG63dt.
Cannot restore Volume Group vg0 with 1 PVs marked as missing.
Restore failed.
/etc/lvm/backups/vg0 has the following for the physical volume:
physical_volumes {
pv0 {
id = "20zG25-H8MU-UQPf-u0hD-NftW-ngsC-mG63dt"
device = "/dev/sda5" # Hint only
status = ["ALLOCATABLE"]
flags = []
dev_size = 4292870143 # 1.99902 Terabytes
pe_start = 384
pe_count = 524031 # 1.99902 Terabytes
}
}
fdisk -l /dev/sda shows the following:
[root@apollo ~]# fdisk -l /dev/sda
Disk /dev/sda: 6000.1 GB, 6000069312512 bytes
64 heads, 32 sectors/track, 5722112 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000188b7
Device Boot Start End Blocks Id System
/dev/sda1 2 32768 33553408 82 Linux swap / Solaris
/dev/sda2 32769 33280 524288 83 Linux
/dev/sda3 33281 1081856 1073741824 83 Linux
/dev/sda4 1081857 3177984 2146435072 85 Linux extended
/dev/sda5 1081857 3177984 2146435071+ 8e Linux LVM
The server is running a 4 disk HW RAID10 which seems perfectly healthy according to megacli and smartd.
The only odd message in /var/log/messages is the following which shows up every couple of hours:
Jun 10 09:41:57 apollo udevd[527]: failed to create queue file: No space left on device
Output of df -h
[root@apollo ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 1016G 119G 847G 13% /
/dev/sda2 508M 67M 416M 14% /boot
Does anyone have any ideas what to do next? The VMs are all running fine at the moment apart from not being able to snapshot them.
Updated with extra info
It's not a lack of inodes:
[root@apollo ~]# df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/sda3 67108864 48066 67060798 1% /
/dev/sda2 32768 47 32721 1% /boot
pvs, vgs & lvs either output nothing or "No volume groups found".