[ILUG] LVM oddity

[Niall O Broin]

Having a little problem here with LVM which is bothering me somewhat:

server7:~# vgscan
   Reading all physical volumes.  This may take a while...
   /dev/dm-3: read failed after 0 of 4096 at 25769738240: Input/ 
output error
   /dev/dm-3: read failed after 0 of 4096 at 0: Input/output error
   /dev/dm-7: read failed after 0 of 4096 at 25769738240: Input/ 
output error
   /dev/dm-7: read failed after 0 of 4096 at 0: Input/output error
   Found volume group "sda4_vg" using metadata type lvm2

What are the read failures?


server7:~# lvscan
   /dev/dm-3: read failed after 0 of 4096 at 0: Input/output error
   /dev/dm-7: read failed after 0 of 4096 at 0: Input/output error
   inactive Original '/dev/sda4_vg/host1-disk' [24.00 GB] inherit
   inactive Original '/dev/sda4_vg/host2-disk' [24.00 GB] inherit
   ACTIVE            '/dev/sda4_vg/host1-swap' [2.00 GB] inherit
   ACTIVE            '/dev/sda4_vg/host2-swap' [2.00 GB] inherit
   ACTIVE            '/dev/sda4_vg/host4-swap' [1.00 GB] inherit
   ACTIVE            '/dev/sda4_vg/host4-disk' [4.00 GB] inherit
   inactive Snapshot '/dev/sda4_vg/host1snap' [2.00 GB] inherit
   inactive Snapshot '/dev/sda4_vg/host2snap' [2.00 GB] inherit

A little googling found references to the same issue, and a  
suggestion that removing the snapshots fixes it. So, I tried that, as  
the snapshots are not needed

server7:~# lvremove /dev/sda4_vg/host2snap
   /dev/dm-3: read failed after 0 of 4096 at 0: Input/output error
   /dev/dm-7: read failed after 0 of 4096 at 0: Input/output error
Do you really want to remove active logical volume "host2snap"? [y/n]: y
Segmentation fault

host1 and host2 are two quite busy Xen domU web servers, whose root  
disks are on host1-disk and host2-disk, so I'm a little worried about  
this, to say the least (although the domUs seem to be running quite  
happily).


Niall