Reducing space in LVM partition and removing disk from the server
You might have allocated more space to lvm partition for future use but now its not required hence you are planning to reduce the LVM partition and to remove the disk from the server. This can be done only offline so you need to get downtime if there is any application holding this filesystem to unmount it to perform below steps.
suse11-1:~ # df -h Filesystem Size Used Avail Use% Mounted on /dev/vda2 19G 3.6G 14G 21% / udev 435M 148K 435M 1% /dev tmpfs 435M 796K 434M 1% /dev/shm /dev/mapper/testvg-testlv 8.9G 271M 8.2G 4% /test suse11-1:~ #
suse11-1:~ # umount /test/ suse11-1:~ # df -h Filesystem Size Used Avail Use% Mounted on /dev/vda2 19G 3.6G 14G 21% / udev 435M 148K 435M 1% /dev tmpfs 435M 796K 434M 1% /dev/shm suse11-1:~ #
suse11-1:~ # e2fsck -f /dev/mapper/testvg-testlv e2fsck 1.41.9 (22-Aug-2009) Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information /dev/mapper/testvg-testlv: 13/588672 files (15.4% non-contiguous), 106205/2359296 blocks suse11-1:~ #
suse11-1:~ # resize2fs /dev/mapper/testvg-testlv 3G resize2fs 1.41.9 (22-Aug-2009) Resizing the filesystem on /dev/mapper/testvg-testlv to 786432 (4k) blocks. The filesystem on /dev/mapper/testvg-testlv is now 786432 blocks long. suse11-1:~ #
suse11-1:~ # lvreduce -L 3G /dev/mapper/testvg-testlv WARNING: Reducing active logical volume to 3.00 GiB THIS MAY DESTROY YOUR DATA (filesystem etc.) Do you really want to reduce testlv? [y/n]: y Reducing logical volume testlv to 3.00 GiB Logical volume testlv successfully resized suse11-1:~ #
suse11-1:~ # mount /dev/mapper/testvg-testlv /test/ suse11-1:~ # df -h Filesystem Size Used Avail Use% Mounted on /dev/vda2 19G 3.6G 14G 21% / udev 435M 148K 435M 1% /dev tmpfs 435M 796K 434M 1% /dev/shm /dev/mapper/testvg-testlv 3.0G 264M 2.6G 10% /test suse11-1:~ #
In other way we can reduce the LVM partition using single command with -r option as shown below but this will work in RHEL 5 and later. I tried this in Suse 11 SP4 and worked fine but I’m not sure this will work in earlier versions of Suse 11 SP4
suse11-1:~ # df -h Filesystem Size Used Avail Use% Mounted on /dev/vda2 19G 3.6G 14G 21% / udev 435M 148K 435M 1% /dev tmpfs 435M 796K 434M 1% /dev/shm /dev/mapper/testvg-testlv 8.9G 271M 8.2G 4% /test
suse11-1:~ # umount /test/ suse11-1:~ # df -h Filesystem Size Used Avail Use% Mounted on /dev/vda2 19G 3.6G 14G 21% / udev 435M 148K 435M 1% /dev tmpfs 435M 796K 434M 1% /dev/shm
suse11-1:~ # lvreduce -L 3G -r /dev/testvg/testlv fsck from util-linux 2.19.1 /dev/mapper/testvg-testlv: 13/588672 files (15.4% non-contiguous), 106205/2359296 blocks resize2fs 1.41.9 (22-Aug-2009) Resizing the filesystem on /dev/mapper/testvg-testlv to 786432 (4k) blocks. The filesystem on /dev/mapper/testvg-testlv is now 786432 blocks long. Reducing logical volume testlv to 3.00 GiB Logical volume testlv successfully resized suse11-1:~ #
suse11-1:~ # mount /dev/testvg/testlv /test/ suse11-1:~ # df -h Filesystem Size Used Avail Use% Mounted on /dev/vda2 19G 3.6G 14G 21% / udev 435M 148K 435M 1% /dev tmpfs 435M 796K 434M 1% /dev/shm /dev/mapper/testvg-testlv 3.0G 264M 2.6G 10% /test suse11-1:~ #
suse11-1:~ # vgs VG #PV #LV #SN Attr VSize VFree testvg 5 1 0 wz--n- 9.98g 6.98g suse11-1:~ # pvs PV VG Fmt Attr PSize PFree /dev/sda testvg lvm2 a-- 2.00g 0 /dev/sdb testvg lvm2 a-- 2.00g 1016.00m /dev/sdc testvg lvm2 a-- 2.00g 2.00g /dev/vdb testvg lvm2 a-- 2.00g 2.00g /dev/vdc testvg lvm2 a-- 2.00g 2.00g
suse11-1:~ # lvs LV VG Attr LSize Pool Origin Data% Move Log Copy% Convert testlv testvg -wi-ao--- 3.00g
Now we have enough free space available in Volume group. You can allocate this space to another LVM in the same VG or you can reclaim the disks if don’t need space to any other file systems in the server
suse11-1:~ # vgs VG #PV #LV #SN Attr VSize VFree testvg 5 1 0 wz--n- 9.98g 6.98g
suse11-1:~ # pvs PV VG Fmt Attr PSize PFree /dev/sda testvg lvm2 a-- 2.00g 0 /dev/sdb testvg lvm2 a-- 2.00g 1016.00m /dev/sdc testvg lvm2 a-- 2.00g 2.00g /dev/vdb testvg lvm2 a-- 2.00g 2.00g /dev/vdc testvg lvm2 a-- 2.00g 2.00g suse11-1:~ #
Remove the disks from the Volume Group
suse11-1:~ # vgreduce testvg /dev/sdc /dev/vdb /dev/vdc Removed "/dev/sdc" from volume group "testvg" Removed "/dev/vdb" from volume group "testvg" Removed "/dev/vdc" from volume group "testvg"
suse11-1:~ # vgs VG #PV #LV #SN Attr VSize VFree testvg 2 1 0 wz--n- 3.99g 1016.00m
Now you can see from pvs command that disks are not assigned to any of the volume group
suse11-1:~ # pvs PV VG Fmt Attr PSize PFree /dev/sda testvg lvm2 a-- 2.00g 0 /dev/sdb testvg lvm2 a-- 2.00g 1016.00m /dev/sdc lvm2 a-- 2.00g 2.00g /dev/vdb lvm2 a-- 2.00g 2.00g /dev/vdc lvm2 a-- 2.00g 2.00g
Remove the disks from PV
suse11-1:~ # pvremove /dev/sdc /dev/vdb /dev/vdc Labels on physical volume "/dev/sdc" successfully wiped Labels on physical volume "/dev/vdb" successfully wiped Labels on physical volume "/dev/vdc" successfully wiped
Now disks are removed from the PV
suse11-1:~ # pvs PV VG Fmt Attr PSize PFree /dev/sda testvg lvm2 a-- 2.00g 0 /dev/sdb testvg lvm2 a-- 2.00g 1016.00m
But still disks are visible to the OS, this can be found thru cat /proc/partitions command
suse11-1:~ # cat /proc/partitions major minor #blocks name 253 0 20971520 vda 253 1 1532928 vda1 253 2 19437568 vda2 253 16 2097152 vdb 253 32 2097152 vdc 8 16 2097152 sdb 8 0 2097152 sda 8 32 2097152 sdc 252 0 3145728 dm-0
If you partition the disk before adding to the PV then remove the partition before removing the disk from the OS level.
suse11-1:/test # echo 1 > /sys/block/sdc/device/delete suse11-1:/test #
Finally inform to Vmware or SAN team to reclaim the disk from the server otherwise it woul.d have show again in OS level if you scan or reboot the server.
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