topic Re: How to replace a mirrored VxVM root disk in Operating System - HP-UX

How to replace a mirrored VxVM root disk

Steven Hargus_3 — Mon, 27 Feb 2006 16:48:53 GMT

Hello -

I have a server with the two internal disks formatted with VxVM running HP-UX 11iV2. The two disks are mirrored using vxrootmir. I have the basic VxVM license.

One of the internal disks is reporting that it will fail soon. I do not know yet if the disk is the primary or the mirror copy.

What steps do I need to do to replace the disk and restore the LIF and boot info?

Thanks

Re: How to replace a mirrored VxVM root disk

Geoff Wild — Mon, 27 Feb 2006 16:53:02 GMT

Check out:

http://docs.hp.com/en/5991-1838/5991-1838.pdf

There are sections on mirroring root...in chapter 2...

Rgds...Geoff

Re: How to replace a mirrored VxVM root disk

Senthil Kumar .A_1 — Mon, 27 Feb 2006 23:32:07 GMT

Hi steven,

Please let us know the output of the following commands. We will let you know how to replace teh disk step by step, analyzing the data.

vxdisk list
vxprint -t
vxprint -ht
echo "boot_string/S" | adb /stand/vmunix /dev/kmem
ioscan -funC disk

And the error messages related to the disk failure (probably from syslog or dmesg).

Once you give these outputs, we will give the step by step instructions with commands.

Regards,
Senthil Kumar .A

Re: How to replace a mirrored VxVM root disk

Steven Hargus_3 — Tue, 28 Feb 2006 12:40:11 GMT

I have attached a file with the output from the commands.

The drive has not failed yet. We got an EMS message as follows:

Summary:
Disk at hardware path 0/1/1/0.1.0 : A SMART event has occurred.

Description of Error:

The drive has predicted that it will fail in the near future. Contact
your HP support representative as soon as possible.

Probable Cause / Recommended Action:

A SMART event has occurred. The drive has detected a serious condition in
itself that indicates it will soon fail. Contact your HP support
representative as soon as possible. Back up the data on the drive now!

Re: How to replace a mirrored VxVM root disk

jamesps — Tue, 28 Feb 2006 13:33:28 GMT

One way you can do it is using vxdiskadm like this:

Launch vxdiskadm
Choose option 3 "Remove a disk for replacement"
Follow the prompts then finally remove the drive.
Insert the new disk.
Launch vxdiskadm again
Choose option 4 "Replace a failed or removed disk"

The new disk will take the name of the old one and the VxVM will take care of the rest.

Hope this helps,
james

Re: How to replace a mirrored VxVM root disk

Steven Hargus_3 — Tue, 28 Feb 2006 13:39:24 GMT

But will it fix the boot code?

Re: How to replace a mirrored VxVM root disk

Alzhy — Tue, 28 Feb 2006 23:05:20 GMT

Read:

http://docs.hp.com/en/5187-1369/ch02s07.html#i1364736

Re: How to replace a mirrored VxVM root disk

Alzhy — Tue, 28 Feb 2006 23:07:10 GMT

And most specially:

http://docs.hp.com/en/5187-1374/ch02s02.html

Hope this helps.

Re: How to replace a mirrored VxVM root disk

Senthil Kumar .A_1 — Tue, 28 Feb 2006 23:17:26 GMT

Hi steven,

I'm in the process of creating the doc with commands to fix your issue, I will post it immediately once it is done. It would take about 15 minutes,

Meanwhile u haven't given the error message, meaning, you havent indicated which disk is failing.

regards,
Senthil Kumar .A

Re: How to replace a mirrored VxVM root disk

Senthil Kumar .A_1 — Tue, 28 Feb 2006 23:19:16 GMT

ignore my disk failure query .. got it from ur post..

:( I always do this mistake not noticing the post properly, I was concentrating on ur doc attachment.

nevermind,

I building your process..

Regards,
Senthil Kumar .A

Re: How to replace a mirrored VxVM root disk

Senthil Kumar .A_1 — Tue, 28 Feb 2006 23:38:59 GMT

Hi steven,

I would prefer u seeing the txt file attachment. It contains the same instruction that is given below.

Firstly, the system has booted from, /dev/dsk/c2t0d0 as the adb output suggests.
It is the second disk /dev/dsk/c2t1d0 from which it is not booted from and is also the one failing making our procedure easy.
The steps for replacing the second disk is as follows. Here I have given basic commands to
achieve it,

1) You need to disassociate the plexes associated from the second disk,

vxplex -g rootdg homevol-02 optvol-02 rootvol-02 standvol-02 swapvol-02 tmpvol-02 usrvol-02 varvol-02

verify the action,
vxprint -t

2) you need to delete the plexes that are disassociated now.

vxedit -g rootdg -r rm homevol-02 optvol-02 rootvol-02 standvol-02 swapvol-02 tmpvol-02 usrvol-02 varvol-02

verify the action,
vxprint -t

3) remove the second disk from the rootdg,

vxdg -g rootdg rmdisk rootdisk02

Now you can repalce the second disk, say if it is hot pluggable , u do not have any issues,
follow the instruction by the vendor, If it is not hotplugable, shutdown the unix box. replace
disk with the new one. Boot the machine. Now run the "ioscan -fnC disk" command. Let us assume
the device file for the new disk is the same as the repalced one. Now you can perform the mirror-
ing with the following command.

/etc/vx/bin/vxrootmir -v c2t1d0

This process might take about 20 minutes, verify it by issuing the following command.

vxprint -t

Regards,
Senthil Kumar .A

Re: How to replace a mirrored VxVM root disk

Senthil Kumar .A_1 — Tue, 28 Feb 2006 23:42:27 GMT

Important....

In the second step command, i have missed a keyword "dis"...please use the following..

vxplex -g rootdg dis homevol-02 optvol-02 rootvol-02 standvol-02 swapvol-02 tmpvol-02 usrvol-02 varvol-02

Million apologies..

Senthil

Re: How to replace a mirrored VxVM root disk

Senthil Kumar .A_1 — Tue, 28 Feb 2006 23:45:33 GMT

Hi steven,

:( scrap my last 2 posts..

the corrected version of the attachment and post is this one..

Firstly, the system has booted from, /dev/dsk/c2t0d0 as the adb output suggests.
It is the second disk /dev/dsk/c2t1d0 from which it is not booted from, is the one failing.
The steps for replacing the second disk is as follows. Here I have given basic commands to
achieve it,

1) You need to disassociate the plexes associated from the second disk,

vxplex -g rootdg dis homevol-02 optvol-02 rootvol-02 standvol-02 swapvol-02 tmpvol-02 usrvol-02 varvol-02

verify the action,
vxprint -t

2) you need to delete the plexes that are disassociated now.

vxedit -g rootdg -r rm homevol-02 optvol-02 rootvol-02 standvol-02 swapvol-02 tmpvol-02 usrvol-02 varvol-02

verify the action,
vxprint -t

3) remove the second disk from the rootdg,

vxdg -g rootdg rmdisk rootdisk02

Now you can repalce the second disk, say if it is hot pluggable , u do not ahve any issues,
follow the istruction by the vendor, If it is not hotplugable, shutdown the unix box. replace
disk with the new one. Boot the machine. Now run the "ioscan -fnC disk" command. Let us assume
the device file for the new disk is the same as the repalce one. Now you can perform the mirror-
ing with the following command.

/etc/vx/bin/vxrootmir -v c2t1d0

This process might take about 20 minutes, verify it by issuing the following command.

vxprint -t

Regards,
Senthil Kumar .A

Re: How to replace a mirrored VxVM root disk

Senthil Kumar .A_1 — Tue, 28 Feb 2006 23:52:24 GMT

If you want my online support,

Please free to contact me online with the following chat messengers,

yahoo - senthil_anantha
msn - senthil_anantha@hotmail.com
aol - senthilanantha@aim.com

regards,
Senthil

Re: How to replace a mirrored VxVM root disk

Alzhy — Wed, 01 Mar 2006 09:46:31 GMT

Steven,

Senthil's detailed process is correct as is depicted in the official VxVM documents - which I think misses those tiny but important details..

Senthil, I sent you an email to those 3 addresses you posted. Please check them out.. I've a question for you.