topic Re: IVEXTEND in Operating System - HP-UX

IVEXTEND

YOGI_3 — Mon, 21 Nov 2005 03:10:05 GMT

Hello all..
I am extending one vg by 200GB by following command..
But its not extended by 200GB....
Please refer the following error..screenshot..

yogeshg@mbpscw01/>vgextend /dev/vgstrm02 /dev/dsk/c12t2d2
vgextend: Warning: Max_PE_per_PV for the volume group (5759) too small for this PV (25599).
Using only 5759 PEs from this physical volume.
Volume group "/dev/vgstrm02" has been successfully extended.
Volume Group configuration for /dev/vgstrm02 has been saved in /etc/lvmconf/vgstrm02.conf
yogeshg@mbpscw01/>umount /ixgfs_str9

Re: IVEXTEND

Luk Vandenbussche — Mon, 21 Nov 2005 03:15:10 GMT

Hi Yogi,

This means that the maximum size of a lun that you can add to your VG is

5759 * 8 = 45 GB.

The easiest way is to add 4 Luns of 45 GB to vgstrm02.

You can check the max_pe_per_PV with the command vgdisplay -v vgstrm02

Re: IVEXTEND

RAC_1 — Mon, 21 Nov 2005 03:16:31 GMT

You are limited by no. of PEs in a VG. the max number is 65535. If you have a very big sized disk to beincluded in vg, you should set PE size high.

There is no way to crrect this but only to re-create vg.

man vgcreate for details.

Re: IVEXTEND

Howard Marshall — Mon, 21 Nov 2005 15:42:22 GMT

It sounds like the volume group was created with much smaller physical volumes than the 200 gig you are trying to add to it. In a volume group all of the physical extents PEs must be the same size (in this case 8Meg) and the max pe per pv sets the largest physical volume size that can be added (in this case 45Gig) and its now about 45Gig

A couple of options seem obvious,

One, split the 200gig partition up into smaller luns or smaller disks in the array subsystem and add the bunch of smaller disks to the vg (this will be harder to manage in the future sense you will use up more of the max pvs per vg)

Two, create a new vg with just the 200 gig disk in it and migrate the logical volumes over to it one at a time. (this may take several reboots but possibly not as much down time)

Three, create backups of all the file systems and logical volumes, drop the existing vg, and recreate the vg with all the physical volumes in it, recreate the lvs and file systems, and restore from backup (this will take more down time but should only take one reboot)

Hope that helps some

Re: IVEXTEND

James R. Ferguson — Mon, 21 Nov 2005 15:52:54 GMT

Hi Yogi:

The message means just what it says -- namely that only 5759 PE were used. Multiply this by your PESIZE and you will see how much of the 200GB you wanted was used.

The geometry of the LVM header is fixed during 'vgcreate' The '-e max_pe' argument sets the maximum number of physical extents
that can be allocated from any one of the physical volumes in the volume group begin created. You have reached this limit.

The only way to change this is to destroy and recreate the volume group.

Your 'vgextned' was partially successful; taht is, it did as much as it could.

Regards!

...JRF...