Enabling distributed allocation policy on existing LV

[Marc Roger]

Is it possible to enable the distributed allocation policy on existing logical volumes that were extended without this policy ?
I have modified the LV configuration with
lvchange -s g -D f /dev/vg02/lvol1
but what do I do next to effectively spread the LEs on the multiple PVs ?

[Steven Sim Kok Leong · Accepted solution]

Hi,

With the -D f option, what you will be getting is a partially-distributed LV. The lvchange will have no effects on existing LEs. lvdisplay will show the LV as partially-distributed.

However, new LEs within this LV will follow the distributed allocation policy ie. when you lvextend this LV eg.

# lvextend -L 450 /dev/vgXX/lvolYY

To verify the distribution of new LEs, you can perform an lvdisplay/pvdisplay and check the LE numbers against the PV numbers.

However, if you wish to shift existing LEs to be distributed, I believe the only way is to perform data backup and restore, remove and re-create the LV via lvcreate with the -D option.

Hope this helps. Regards.

Steven Sim Kok Leong