Balancing LVM Virtual group between disks

Question

I have an LVM virtual group with 4x disks, on this virtual group there are several logical volumes. However all the logical volumes have been placed on the first disk in the group resulting in poor performance. It it possible to rebalance the logical volumes so that they are spread roughly evenly over the 4 disks?

score 6 · Answer 1 · answered Sep 25 '21 at 12:32

6

To balance the spread of LV on all disks you can execute command like this:

lvconvert --stripes 4 vg/lv01

This will stripe the LV lv01 to all 4 disks.

Also you can consider change the stripe size (depend a lot of type of data you store on this LV)

lvconvert -I 64k vg/lv01

P.S. moving around LV on different PV rarely will help.

answered Sep 25 '21 at 12:32

Romeo Ninov

17,484

3

Does it rebalance immediately and automatically? Or does it only apply to new data written? – Michael Hampton Sep 26 '21 at 00:23
1

@MichaelHampton, when you execute the command it rebalance the data (it take some time) – Romeo Ninov Sep 26 '21 at 04:27

score 4 · Answer 2 · answered Sep 25 '21 at 11:54

4

You can use pvmove to move LVs from one PV to another:

pvmove -n <logical_volume> <pv_from> <pv_to>

so for example

pvmove -n lvol1 /dev/sdb1 /dev/sdc1

to move lvol1 from sdb1 to sdc1.

answered Sep 25 '21 at 11:54

Vojtech Trefny

18,146

Balancing LVM Virtual group between disks

2 Answers2