device-mapper: remove ioctl failed: Device or resource busy



[root@QA mapper]# ls -ltr /dev/mapper
lrwxrwxrwx. 1 root root 8 Oct 23 09:34 newUUID-lv_root -> ../dm-17

[root@QA mapper]# dmsetup remove newUUID-lv_root

[root@QA mapper]# dmsetup remove --force /dev/mapper/vg_qa-snap2
[root@QA mapper]#

[root@QA mapper]# dmsetup remove --force /dev/mapper/vg_qa-snap2
device-mapper: remove ioctl on vg_qa-snap2 failed: Device or resource busy
Command failed

[root@QA mapper]# dmsetup info -c /dev/mapper/vg_qa-snap2
Name             Maj Min Stat Open Targ Event  UUID
vg_qa-snap2      253  16 L--w    1    1      0 part2-LVM-HZDfYZOYXTlZCP8n3Z8mmMACc05JJdUVjkfBxS7oshjjCk7pT6DojiR3g01XXUMf

[root@QA mapper]# dmsetup status | grep snap
vg_qa-snap2: 0 20445184 error
vg_qa-kickstart--first: 0 20971520 snapshot-origin

[root@QA mapper]# kpartx -av /dev/mapper/vg_qa-snap
add map vg_qa-snap1 (253:15): 0 524288 linear /dev/mapper/vg_qa-snap 2048
add map vg_qa-snap2 (253:16): 0 20445184 linear /dev/mapper/vg_qa-snap 526336

[root@QA mapper]# pvs
  PV                      VG      Fmt  Attr PSize   PFree
  /dev/mapper/vg_qa-snap2 newUUID lvm2 a--    9.75g      0
  /dev/sda2               vg_qa   lvm2 a--  232.63g      0
  /dev/sdb1               vg_qa   lvm2 a--  931.51g 724.84g
[root@QA mapper]# vgchange -ay
  1 logical volume(s) in volume group "newUUID" now active
  13 logical volume(s) in volume group "vg_qa" now active

[root@QA mapper]# lvscan | grep UUID
  ACTIVE            '/dev/newUUID/lv_root' [9.75 GiB] inherit

The UUID named newUUID was trapped with an error as described in the quote above, once that was clear it was able to become active.

[root@QA mapper]# mount /dev/newUUID/lv_root /mnt
[root@QA mapper]# ls /mnt
bin  boot  dev  etc  home  lib  lib64  lost+found  media  mnt  opt  proc  root  sbin  selinux  srv  sys  tmp  usr  var

The logical volume was named /dev/lvols/ubuntu64

At first

$lvremove /dev/lvols/ubuntu64

This command couldn’t remove the logical volume the next command I tried was

root@manager-desktop:~# dmsetup remove --force /dev/lvols/ubuntu64
device-mapper: remove ioctl failed: Device or resource busy
Command failed

So some process is using this logical volume and to find the process id the next command was

root@manager-desktop:~# lsof /dev/lvols/ubuntu64
COMMAND   PID USER   FD   TYPE DEVICE SIZE/OFF   NODE NAME
vblade  31213 root    3u   BLK  252,4      0t0 115749 /dev/lvols/../mapper/lvols-ubuntu64

root@manager-desktop:~# kill -9 31213

Now issued the commands

root@manager-desktop:~# dmsetup remove --force /dev/lvols/ubuntu64

root@manager-desktop:~# lvremove /dev/lvols/ubuntu64
 Logical volume "ubuntu64" successfully removed