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