topic Re: Un-mirror vg00 & remove disk in Operating System - HP-UX

Un-mirror vg00 & remove disk

michael valentin — Tue, 31 Jul 2001 18:59:17 GMT

We have T500, HP-UX 10.20 & vg00 configured as HFS. Recently created two mirrors of a 1GB (vg00) bootable disk to two 4GB disk (now have 3 copies). The 1GB is the primary copy. The two 4 GB disks are also bootable (tested it!!). We wanted to get rid of the 1GB but since it's the primary and it's vg00, I'm afraid i might mess it up. Is lvreduce the right command to use??

Re: Un-mirror vg00 & remove disk

Victor BERRIDGE — Tue, 31 Jul 2001 19:12:39 GMT

Hi,
I havent tried with rootvg but yes I use lvreduce:
lvreduce -m 0 /dev/r5vg06/lvol1 /dev/dsk/c8t0d4
followed by vgreduce:
vgreduce r5vg06 /dev/dsk/c8t0d4

ALl the best

Victor

Re: Un-mirror vg00 & remove disk

Mark Mitchell — Tue, 31 Jul 2001 19:17:23 GMT

Good chance that vgreduce -m 0 will remove both mirrors. Try to reduce the disk from the volume group by address. But only after #setboot -a to the new disk address and boot from it first. Then make changes.

Re: Un-mirror vg00 & remove disk

michael valentin — Tue, 31 Jul 2001 19:23:18 GMT

Thanx for the quick replies. Shouldn't I do lvreduce -m 1 /dev/dsk/c#t#d# since I'm just removing one of the mirror. The mirror vg00 goes like this: 1GB -> 4GB -> 4GB and I wanted to remove the 1GB and leave the two 4GB.

Re: Un-mirror vg00 & remove disk

Victor BERRIDGE — Tue, 31 Jul 2001 19:34:15 GMT

yes, my example was with 2 copies...

Re: Un-mirror vg00 & remove disk

James R. Ferguson — Tue, 31 Jul 2001 19:34:29 GMT

Hi Michael:

I haven't tried this one either, BUT:

Make sure that you have applied PHCO_23437 (for 10.20). This LVM patch corrects some serious problems with 'lvlnboot'.

Reduce the mirror on the physical disk you want to decommission. For each logical volume (N), do:

# lvreduce -m 0 /dev/vg00/lvol${N} /dev/dsk/cXtYdZ

Then, 'vgreduce' the physical disk:

# vgreduce /dev/vg00 /dev/dsk/cXtYdZ

Lastly, correct your boot information!

# lvlnboot -R
# lvlnboot -v #...to verify...

...JRF...

Re: Un-mirror vg00 & remove disk

linuxfan — Thu, 02 Aug 2001 03:08:47 GMT

Hi,

Just wanted to bring up a point that /dev/vg00/lvol3 should be the last logical volume to be reduced.

Also something i wasn't sure of, When you mirrored the 1GB disk with a 4GB disk, are you able to utilize the full capacity of the 4GB disk? As far as i know the easiest way to migrate a 1GB root disk to a 4GB disk is through ignite/ux.

Would appreciate your answer to my question.

-I am RU

Re: Un-mirror vg00 & remove disk

michael valentin — Thu, 02 Aug 2001 12:29:28 GMT

Hi Ramesh. Yes, I was able to fully utilized the 4GB to mirror the 1GB.