Monthly Archives: August 2015

How to remove the read failed after 0 of 4096 I/O error

from: https://freeshell.de/~jose/317/kludges/how-to-temove-the-read-failed-after-0-of-4096-io-error/

Recently in a very old server I had to remove a disk. My server was composed by two physical volumes: a RAID5 volume, shown as /dev/sda to the operating system by the SCSI controller, and a single hard disk as /dev/sdb.

My /dev/sdb, since there is no way to have a new disk with the same geometry, I decided to remove it.
The bios utility of my SCSI controller is quite strange and I cannot remove my une-disk logical volume without remove all the configuration.

root@arch:~# pvdisplay
  /dev/sdb: read failed after 0 of 4096 at 0: input/output Error
  /dev/sdb: read failed after 0 of 4096 at 146695716864: input/output Error
  /dev/sdb: read failed after 0 of 4096 at 146695774208: input/output Error
  /dev/sdb: read failed after 0 of 4096 at 4096: input/output Error
  — Physical volume —
  PV Name               /dev/sda1
  VG Name               vg_system
  PV Size               838,12 GiB / not usable 2,00 MiB
  Allocatable           yes
  PE Size               4,00 MiB
  Total PE              214559
  Free PE               21184
  Allocated PE          193375
  PV UUID               ZQQwAs-yGgP-LZXk-3cTy-yaOb-gijr-bnUCz4

So I’d better to leave my controller untouched and tell my linux CentOS to forget the /dev/sdb disk.

root@arch:~# echo 1 > /sys/block/sdb/device/delete