topic LVM and LUN resizing in Operating System - Linux

LVM and LUN resizing

Domenico Viggiani — Wed, 30 Jun 2004 10:27:23 GMT

Hi,
this is my setup:
- server HP Proliant DL740 with Red Hat AS 3 (kernel 2.4.21-9ELsmp) with all
updates installed
- two Host Bus Adapter FC2214 with qla2x00 driver from HP (v.6.06.50)
- a SAN with an HP EVA3000 disk-array
- LVM

Does LVM support extending LUN size?
I extended size of an existing LUN from my EVA CommandView but vgdisplay
shows me always the original size (with no free physical extents). No change
if I reboot, I need to destroy and re-create volume group.

Have I some other chance?

Thanks
Domenico Viggiani

Re: LVM and LUN resizing

Stuart Browne — Wed, 30 Jun 2004 18:25:28 GMT

If you've extended the LUN, then you should be able to use 'vgextend' to expand the volume group accordingly.

From there, you should be able to add new logical volumes or extend existing partitions.

Re: LVM and LUN resizing

Domenico Viggiani — Thu, 01 Jul 2004 02:04:54 GMT

'vgextend' adds physical volumes to a volume group; it doesn't permit extending vg if pv is enlarged.

Re: LVM and LUN resizing

Stuart Browne — Thu, 01 Jul 2004 02:38:06 GMT

'vgextend' extends a volume group, you are right.

However a phiscal volume cannot be extended (no 'pvextend' command), so my apologies for the error.

Just add a new PV using the new space, and vgextend into it. A VG can quite happily span multiple PV's.

I used s similar method when migrating out a error ridden disk at home. The LVM howto explains most of the steps in various sections (don't have a copy in front of me at this moment however).

Re: LVM and LUN resizing

Domenico Viggiani — Thu, 01 Jul 2004 02:44:45 GMT

Ok, I know LVM basics.
From linux-lvm mailing-list, I learned that LVM1 doesn't support LUN extension.
Neither it is possible on HP-UX!