Table of Contents
LVM checksum error
Error description
The problem can begin with the inaccessibility (ping, VNC console, serial console) of a vhost. The vhost can be shut off (virsh destroy vhost), but the vhost cannot be restarted (virsh start vhost). The command virsh start either does not deliver any output at all or it delivers an error message stating that the file or device for the virtual disk cannot be read.
Commands for displaying the LVM volume group (vgs, vgdisplay) of the virtual disk of the affected vhost deliver checksum errors. On KVM hosts that are connected to the same volume group the commands vgs and vgdisplay also display no LVM partitions.
Failure cause
After findings so far the checksum error is not related to the data content of the LVM partition. It is related to errors in the meta data information of the LVM device. The cause of the meta data corruption is unknown.
Solution
The following command checks and repairs the LVM meta data information. When several KVM hosts are connected to the LVM device, the command only needs to be executed on one host.
vgcfgrestore <vg-name>
After execution of the command vgcfgrestore commands like e.g. vgs and lvs display LVM groups and partitions again, access to the partitions is possible again and the vhost shut off before can be restarted.