topic Re: Root disk replacement in Operating System - HP-UX

Root disk replacement

AIMC — Thu, 24 Jun 2004 08:20:49 GMT

Hi,

In a HP rp8420, can a failed mirrored root disk be replaced online?

In general can a mirrored root disk be replaced online if the disk is hot pluggable?

Aidan

Re: Root disk replacement

Pete Randall — Thu, 24 Jun 2004 08:23:43 GMT

Aidan,

Absolutely, that's the whole point. Swap the new disk in, run vgcfgrestore, then vgchange -a y vg00, then vgsync and you're home free!

Pete

Re: Root disk replacement

Geoff Wild — Thu, 24 Jun 2004 08:24:07 GMT

Yes and yes.

1) If the disk is completely "dead", such as if you run ioscan and status is "no_hw" then you can hot swap the disk online.

2) However in circumstances where the disk has not fully failed please do one of the following to avoid data corruption :

a) reduce mirror before replacing the disk
b) deactivate VG before replacing the disk
c) shutdown system to replace the disk

Rgds...Geoff

Re: Root disk replacement

Ashwani Kashyap — Thu, 24 Jun 2004 08:40:43 GMT

yes and yes and this explains the entire procedure :

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000073905420

Re: Root disk replacement

A. Clay Stephenson — Thu, 24 Jun 2004 09:04:53 GMT

Yes and yes. I have not shutdown to replace a failed disk in at least 5 years and I done many, many disk swaps over that time.

For a disk that has not failed completely, I find that if I do an lvdisplay -v to confirm that all the extents are current on the good disk for all the LVOLS in question then I simply unplug the flaky drive and wait a minute or so. You now have a completely failed disk and can replace without doing a vgreduce.

I make it a practice to keep spare drives on hand eventhough I am on full HP support; in fact, my last action is to place the support call to get a replacement for my spare drive.

Re: Root disk replacement

YoungHwan, Ko — Fri, 25 Jun 2004 04:00:18 GMT

1. Remove the Mirror State.
# lvreduce -m 0 /dev/vg00/lvol1 /dev/dsk/c#t#d#
# lvreduce -m 0 /dev/vg00 /dev/dsk/c#t#d#
.
.
# vgreduce /dev/vg00 /dev/dsk/c#t#d#

2. Confirm the lmvtab file.
# strings /etc/lvmtab

3. Activates the Volume group.
# vgchange -a y vg00

4. Sync the Volume group.
# vgsync vg00