EVA LUNS

[Phil Storer]

On the EVA I have a LUN of 500GB in size. This has been allocated to a volume group on the host system.

Three logical volumes were created of 102400MB and I wanted to add another 2 of the same size. However I was short by about 20Gb.

So I thought I could extend the size of the LUN via the 'Command view EVA' GUI management console and then increase the size of the volume group. BUT it did not work as the Volume Group was still showing as the same size prior to the resizing of the LUN. Here's the steps I followed.

--> Unmount logical volumes (filesystems)
--> vgchange -a n /dev/vg08 (deactivate vol)
--> Extend size of LUN via management GUI
--> vgchange -a y /dev/vg08 (reactivate vol)

vgdisplay -v /dev/vg08 show's the volume group at the same size prior to resize of LUN

Question:

Do I have to blow away the volume group completely before a resize of the LUN and after the resize create the Volume group again and restore from backup the original 3 logical volumes that were present initially OR is there another way?

[Patrick Wallek]

If you are going to extend a LUN on the EVA, and you want to keep only 1 LUN for your VG, then yes you must blow away the VG and recreate it. LVM does not know how to deal with a LUN that changes size after the VG has been created.

However, if you were to create ANOTHER LUN on the EVA of the size you need, you could then extend the VG to include the next LUN (vgextend command) and then create your next LV.

[Phil Storer]

Thanks Patrick, it's what I thought. Your suggestion to create another LUN and 'vgextend' it to the current VG did cross my mind and I may well go for this option if any more space is required for this VG.