topic Re: Cluster shared storage disk problem in Operating System - HP-UX

Cluster shared storage disk problem

Johnny12 — Mon, 03 Nov 2008 22:23:40 GMT

Dear Gurus,

I have 2 HP servers with 11iV1 OS and where service guard is configured on these servers. the servers are then connected to a shared storage disk system with no controllers.

the shared storage contains 4 disks. a logical volume is created on 2 disks and mirrored to 2 other disks.

I have a defected disk on the shared storage. Can you please provide the required steps to replace the defected disk especially that the same logical volume is created on 2 disks and mirrored to 2 other disks.

Thank you in advance

Re: Cluster shared storage disk problem

Johnson Punniyalingam — Tue, 04 Nov 2008 00:07:15 GMT

Hi ,

>> I have a defected disk on the shared storage. Can you please provide the required steps to replace the defected disk especially that the same logical volume is created on 2 disks and mirrored to 2 other disks<<

by understanding of your above post looks that you have mirror copies,

remove tha fauly disk

ioscan -fnC disk --> looks disk to be claimed

# vgcfgrestore -n vgxx /dev/rdsk/cxtxdx
# vgchange -a y vgxx
# vgsync vgxx

Script to run to check status of vgsync:

while true
do
pvdisplay -v /dev/dsk/cxtxdx|grep stale|wc -l sleep 5 done

Thanks,
Johnson

Re: Cluster shared storage disk problem

jaivinder — Tue, 04 Nov 2008 02:59:18 GMT

To replace the faulty disk follow these steps:

1. Find the faulty disk by running:
#ioscan -fnC disk
The disk with Unclaimed status is the faulty one.
#pvchange -a n /dev/rdsk/cxtxdx
2. Replace the faulty disk with new disk.
3. Restore the volume group information the disk
#pvchange -a y /dev/rdsk/cxtxdx
#vgcfgrestore -n /dev/vg01 /dev/rdsk/cxtxdx
#vgchange -a y /dev/vg01
#vgsync vg01

Re: Cluster shared storage disk problem

Johnny12 — Tue, 04 Nov 2008 07:35:05 GMT

Dear All,

Your above procedures are well noted.
Meantime I have the following question:

Since the same logical volume is configured on 2 disks and Mirrored to 2 other disks using MirrorUX software, does replacing a disk of the 2 mirrored disks cause any data corruption to the whole logical volume?

Re: Cluster shared storage disk problem

Johnson Punniyalingam — Tue, 04 Nov 2008 09:16:49 GMT

>>> Since the same logical volume is configured on 2 disks and Mirrored to 2 other disks using MirrorUX software, does replacing a disk of the 2 mirrored disks cause any data corruption to the whole logical volume? <<<

no data corruption will be cause hence your other mirror copies are ok,

that's the purpose of HPUX -mirror software

Thanks,
Johnson

Re: Cluster shared storage disk problem

Ganesan R — Tue, 04 Nov 2008 09:35:02 GMT

Hi,

If you still want to do it safer way follow the below steps.

1. Reduce the mirror from the defective disk

# lvreduce -m 0

2. Replace the defective disk

3. Make sure the disk is online after replacing.(by ioscan)

4. #vgcfgrestore -n

5. #vgchange -a y vgname

6. extend the mirror

#lvextend -m 1

Re: Cluster shared storage disk problem

Johnny12 — Tue, 04 Nov 2008 19:57:30 GMT

Thank you for your above replies.

Meantime can you please advise on which server of the cluster this work should be done?

does it need to be done on both servers or only on one server.

Re: Cluster shared storage disk problem

Johnson Punniyalingam — Wed, 05 Nov 2008 06:24:25 GMT

if your both "Nodes in the Cluster have the defective disk" you need do for both

Thanks,
JOhnson

Re: Cluster shared storage disk problem

Suraj K Sankari — Wed, 05 Nov 2008 07:48:34 GMT

Hi,

To change the faulty disk please refer this attached doc.

Suraj

Re: Cluster shared storage disk problem

Suraj K Sankari — Wed, 05 Nov 2008 07:49:31 GMT

Sorry forget to attached

here is the attached doc

Suraj