[CentOS] logical volume is unreadable

Thu Jul 6 09:43:55 UTC 2017
Volker <volker at openbios.org>

Hi all,

one of my lv has become completely unaccessible. Every read access
results in a buffer io error:

Buffer I/O error on dev dm-13, logical block 0, async page read

this goes for every block in the lv. A ddrescue failed on every single
block.


$ lvdisplay
  --- Logical volume ---
  LV Path                /dev/vg0/lv-vm-tviewer
  LV Name                lv-vm-tviewer
  VG Name                vg0
  LV UUID                XdgHFs-RHVZ-9BAH-1ZSK-yiBX-qqf0-273CtT
  LV Write Access        read/write
  LV Creation host, time host1, 2016-02-06 14:58:19 +0100
  LV snapshot status     INACTIVE destination for lv-vm-tviewer_vorigin
  LV Status              available
  # open                 0
  LV Size                58.59 GiB
  Current LE             15000
  COW-table size         5.86 GiB
  COW-table LE           1500
  Snapshot chunk size    4.00 KiB
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:13


Other lv on the same volume group are healthy. In fact the whole host
runs on the same vg and does not show any problems. Physical volume is a
md raid1 device which is also healthy, as well as its hard disks.

The faulty lv is used as the storage device for a qemu vm, which
suddenly stalled when the io-errors appeared on the host.


Is the any way to diagnose this problem? (centos 7)


Regards
.....Volker