Remove Disks from LVM

Procedure to Remove LVM disk

Make a note of all partitions and disks first
Add new disk and rescan the OS
Add the new Physical Volumes to a Volume Group
Move data from old disk to new disk
Remove disk from VG
Remove disk as physical volume
Run partprobe
Rescan the system

Counting number of existing disks on a system

fdisk -l 2> /dev/null | egrep '^Disk' | grep -v mapper | grep -v identifier | wc -l

Lists disks in scan

ls/sys/class/scsi_host

Scanning new disks on a system

for host in /sys/class/scsi_host/*; do echo "- - -" | sudo tee $host/scan; ls /dev/sd* ; done

RUN A PVSCAN TO CHECK ERRORS ON LVM

pvscan

attach a new disk to volume group

pvcreate /dev/sdd

Extend the volume group (VG ) with above pvdisk

vgextend ubuntu-data /dev/sdd

Move data from old disk to new disk

pvmove /dev/sdb /dev/sdd -v

reduce volume group size

vgreduce ubuntu-data /dev/sdc && vgreduce ubuntu-data /dev/sdb

Remove disks from pv

pvremove /dev/sdb &&pvremove /dev/sdc

rescan scsi bus adapter

for host in /sys/class/scsi_host/*; do echo "- - -" | sudo tee $host/scan; ls /dev/sd* ; done

In this exercise, we attach a new 70GB disk and remove all the existing disks /dev/sdb and /dev/sdc from the system.

root@wiki:~# pvcreate /dev/sdd
Physical volume “/dev/sdd” successfully created.

root@wiki:~# pvs
  PV         VG          Fmt Attr PSize   PFree
  /dev/sda3 ubuntu-vg   lvm2 a–   <9.00g       0
  /dev/sda4 ubuntu-vg   lvm2 a– <10.00g 1016.00m
  /dev/sdb   ubuntu-data lvm2 a– <20.00g       0
  /dev/sdc   ubuntu-data lvm2 a– <30.00g    1.99g
  /dev/sdd               lvm2 —   70.00g   70.00g

root@wiki:~# vgextend ubuntu-data /dev/sdd
Volume group “ubuntu-data” successfully extended

root@wiki:~# pvmove /dev/sdb /dev/sdd -v

    Cluster mirror log daemon is not running.
    Wiping internal VG cache
    Wiping cache of LVM-capable devices
    Archiving volume group “ubuntu-data” metadata (seqno 5).
    Creating logical volume pvmove0
    Moving 5119 extents of logical volume ubuntu-data/ubuntu-lvdata.
    activation/volume_list configuration setting not defined: Checking only host tags for ubuntu-data/ubuntu-lvdata.
    Setting up pvmove in on-disk volume group metadata.
    Creating ubuntu–data-pvmove0
    Loading ubuntu–data-pvmove0 table (253:2)
    Loading ubuntu–data-ubuntu–lvdata table (253:0)
    Suspending ubuntu–data-ubuntu–lvdata (253:0) with device flush
    activation/volume_list configuration setting not defined: Checking only host tags for ubuntu-data/pvmove0.
    Resuming ubuntu–data-pvmove0 (253:2)
    Loading ubuntu–data-pvmove0 table (253:2)
    Suppressed ubuntu–data-pvmove0 (253:2) identical table reload.
    Resuming ubuntu–data-ubuntu–lvdata (253:0)
    Creating volume group backup “/etc/lvm/backup/ubuntu-data” (seqno 6).
    Checking progress before waiting every 15 seconds.
  /dev/sdb: Moved: 0.37%
  /dev/sdb: Moved: 8.22%
  /dev/sdb: Moved: 15.73%
  /dev/sdb: Moved: 23.23%
  /dev/sdb: Moved: 30.26%
  /dev/sdb: Moved: 37.47%
/dev/sdb: Moved: 85.64%
  /dev/sdb: Moved: 92.40%
  /dev/sdb: Moved: 98.63%
  /dev/sdb: Moved: 100.00%
    Polling finished successfully.

root@wiki:~# pvs
  PV         VG          Fmt Attr PSize   PFree
  /dev/sda3 ubuntu-vg   lvm2 a–   <9.00g       0
  /dev/sda4 ubuntu-vg   lvm2 a– <10.00g 1016.00m
  /dev/sdb   ubuntu-data lvm2 a– <20.00g <20.00g
  /dev/sdc   ubuntu-data lvm2 a– <30.00g    1.99g
  /dev/sdd   ubuntu-data lvm2 a– <70.00g   50.00g

root@wiki:~# pvmove /dev/sdc /dev/sdd -v
    Cluster mirror log daemon is not running.
    Wiping internal VG cache
    Wiping cache of LVM-capable devices
    Archiving volume group “ubuntu-data” metadata (seqno 8).
    Creating logical volume pvmove0
    Moving 7169 extents of logical volume ubuntu-data/ubuntu-lvdata.
    activation/volume_list configuration setting not defined: Checking only host tags for ubuntu-data/ubuntu-lvdata.
    Setting up pvmove in on-disk volume group metadata.
    Creating ubuntu–data-pvmove0
    Loading ubuntu–data-pvmove0 table (253:2)
    Loading ubuntu–data-ubuntu–lvdata table (253:0)
    Suspending ubuntu–data-ubuntu–lvdata (253:0) with device flush
    activation/volume_list configuration setting not defined: Checking only host tags for ubuntu-data/pvmove0.
    Resuming ubuntu–data-pvmove0 (253:2)
    Loading ubuntu–data-pvmove0 table (253:2)
    Suppressed ubuntu–data-pvmove0 (253:2) identical table reload.
    Resuming ubuntu–data-ubuntu–lvdata (253:0)
    Creating volume group backup “/etc/lvm/backup/ubuntu-data” (seqno 9).
    Checking progress before waiting every 15 seconds.
  /dev/sdc: Moved: 0.13%
  /dev/sdc: Moved: 5.40%
  /dev/sdc: Moved: 10.09%
  /dev/sdc: Moved: 84.56%
  /dev/sdc: Moved: 89.64%
  /dev/sdc: Moved: 94.63%
  /dev/sdc: Moved: 99.29%
  /dev/sdc: Moved: 100.00%
    Polling finished successfully.

root@wiki:~# pvs
  PV         VG          Fmt Attr PSize   PFree
  /dev/sda3 ubuntu-vg   lvm2 a–   <9.00g       0
  /dev/sda4 ubuntu-vg   lvm2 a– <10.00g 1016.00m
  /dev/sdb   ubuntu-data lvm2 a– <20.00g <20.00g
  /dev/sdc   ubuntu-data lvm2 a– <30.00g <30.00g
  /dev/sdd   ubuntu-data lvm2 a– <70.00g <22.00g

root@wiki:~# vgreduce ubuntu-data /dev/sdb
Removed “/dev/sdb” from volume group “ubuntu-data”

root@wiki:~# vgreduce ubuntu-data /dev/sdc
Removed “/dev/sdc” from volume group “ubuntu-data”

root@wiki:~# pvs
  PV         VG          Fmt Attr PSize   PFree
  /dev/sda3 ubuntu-vg   lvm2 a–   <9.00g       0
  /dev/sda4 ubuntu-vg   lvm2 a– <10.00g 1016.00m
  /dev/sdb               lvm2 —   20.00g   20.00g
  /dev/sdc               lvm2 —   30.00g   30.00g
  /dev/sdd   ubuntu-data lvm2 a– <70.00g <22.00g

root@wiki:~# pvremove /dev/sdb
Labels on physical volume “/dev/sdb” successfully wiped.
root@wiki:~# pvremove /dev/sdc
Labels on physical volume “/dev/sdc” successfully wiped.

root@wiki:~# pvs
  /dev/sdc: read failed after 0 of 4096 at 0: Input/output error
  /dev/sdc: read failed after 0 of 4096 at 32212189184: Input/output error
  /dev/sdc: read failed after 0 of 4096 at 32212246528: Input/output error
  /dev/sdc: read failed after 0 of 4096 at 4096: Input/output error
  PV         VG          Fmt Attr PSize   PFree
  /dev/sda3 ubuntu-vg   lvm2 a–   <9.00g       0
  /dev/sda4 ubuntu-vg   lvm2 a– <10.00g 1016.00m
  /dev/sdd   ubuntu-data lvm2 a– <70.00g <22.00g

root@wiki:~# partprobe

root@wiki:~# pvs
PV         VG          Fmt Attr PSize   PFree
  /dev/sda3 ubuntu-vg   lvm2 a–   <9.00g       0
  /dev/sda4 ubuntu-vg   lvm2 a– <10.00g 1016.00m
  /dev/sdd   ubuntu-data lvm2 a– <70.00g <22.00g

root@wiki:~# df -H
Filesystem                               Size Used Avail Use% Mounted on
udev                                     2.6G     0 2.6G   0% /dev
tmpfs                                    509M 2.3M 507M   1% /run
/dev/mapper/ubuntu–vg-ubuntu–lv         19G   14G 5.0G 73% /
tmpfs                                    2.6G     0 2.6G   0% /dev/shm
tmpfs                                    5.3M 4.1k 5.3M   1% /run/lock
tmpfs                                    2.6G     0 2.6G   0% /sys/fs/cgroup
/dev/loop0                                99M   99M     0 100% /snap/core/9066
/dev/loop1                                99M   99M     0 100% /snap/core/8935
/dev/sda2                                1.1G 160M 794M 17% /boot
/dev/mapper/ubuntu–data-ubuntu–lvdata   51G   49G 298M 100% /data
tmpfs                                    509M   29k 509M   1% /run/user/120
tmpfs                                    509M   46k 509M   1% /run/user/1000
/dev/loop2                                58M   58M     0 100% /snap/core18/1754
/dev/loop3                                99M   99M     0 100% /snap/mpv/1
/dev/loop4                               306M 306M     0 100% /snap/vlc/1620
root@wiki:~#