Mirroring disks during install

[Matt Harrell]

I'm going to be reinstalling HP-UX on a server at a customer site soon. Although I have pretty good experience administering HP-UX servers day-to-day, I've never installed one from scratch. I'm having a hard time finding information on how to set up all my disk mirrors either during, or immediately after, the install. My background in server setup is with Compaq Proliants with SMART Array controllers, which make RAID easy.

Is it possible to do RAID 5 with LVM? If not, I will be looking to simply RAID 1 all disks. If someone could point me to either good online resources or a good book that explains in great detail how to do this, I'd be very grateful. I've already searched through the HP Technical Documentation, and I haven't found exactly what I'm looking for.

[Matt Harrell]

Oops. I forgot to mention the server is a D9000/879 running HP-UX 11.0 (which will be reinstalled).

[harry d brown jr · Accepted solution]

No RAID 5 with LVM, and you have to wait until AFTER you have installed the OS to MIRROR.

And you need a license from HP for MIRROR/ux

live free or die
harry

[S.K. Chan]

Did you find what you need here .. yet ?

http://www.docs.hp.com/hpux/os/11.0/index.html

[A. Clay Stephenson]

Hi:

No you can't do RAID5 with LVM and you can't even do RAID 1 unless the optional Mirror/UX product has been purchased and installed. If you have purchased Mirror/UX then you should put your mirror on a separate SCSI bus.

Here are the steps to mirror an existing typical boot disk. Make sure that your mirror devices match (RAW,COOKED) and that the number of LVOL's is correct:

#!/usr/bin/sh

# This script mirrors the root disks

RAW=/dev/rdsk/c1t5d0
COOKED=/dev/dsk/c1t5d0

pvcreate -f -B ${RAW}
vgextend /dev/vg00 ${COOKED}

mkboot ${RAW}

mkboot -a "hpux -lq (;0)/stand/vmunix" ${RAW}

lvextend -m 1 /dev/vg00/lvol1 ${COOKED}
lvextend -m 1 /dev/vg00/lvol2 ${COOKED}
lvextend -m 1 /dev/vg00/lvol3 ${COOKED}
lvextend -m 1 /dev/vg00/lvol4 ${COOKED}
lvextend -m 1 /dev/vg00/lvol5 ${COOKED}
lvextend -m 1 /dev/vg00/lvol6 ${COOKED}
lvextend -m 1 /dev/vg00/lvol7 ${COOKED}
lvextend -m 1 /dev/vg00/lvol8 ${COOKED}

At this point, you are mirrored but I would do one more thing to enable you to boot from the original boot is case the mirror is dead.

mkboot -a "hpux -lq (;0)/stand/vmunix" ${ORIGRAW}

where ORIGRAW is your original boot disk.

Man pvcreate, vgextend, mkboot. lvextend for details.

Regards, Clay

[Matt Harrell]

Wow. That was fast. There is currently a license for MirrorDisk/UX on the server--I guess I'll just have to figure out how to get it back on after the install. There's going to be a lot of prep work for this.

I did check out that link, and either I'm just missing it, or it didn't really have quite what I was looking for. However, based on the answer I already received here, and the other posts I saw for mirroring disks, I think I'm pretty well set. Can this mirroring be done in SAM, or do I need to run the commands myself?

Thank you.

[A. Clay Stephenson]

Hi again:

The script method is the way to go. All you need to do is make sure the RAW and COOKED values are correct for the MIRROR disk. You also need to do a vgdisplay -v /dev/vg00 beforehand and possibly adjust the number of lvextend calls although the above is typical. Just cut and paste that puppy; make your changes; and let 'er rip.

[Michael Tully]

The other guys have given you some good
information in regards to mirroring and
where to find documentation. Below is a
link to post on actual installation. I
hope that some of the steps contained are
helpful to you as well.

http://forums.itrc.hp.com/cm/QuestionAnswer/1,11866,0x4499e7e60861d511abcd0090277a778c,00.htm

[Sridhar Bhaskarla]

Hi Matt,

Following Clay's procedure, I would add one more mkboot line

Take your lvlnboot -v output

cd /usr/sbin/diag/lif

mkboot -vb updatediaglif2 -p ISL -p HPUX -p AUTO $RAW

Also do the same for the other disk.

Check your previous lvlnboot -v output and run lvlnboot for your root,boot and swap logical volumes.

This is important for offline diagnostics. Make sure you have MAPPER2 listed in the "lifls $DSK" for both the disks.

-Sri

[Bill Hassell]

RAID 5 in opsystem software requires an enormous amount of overhead for every disk I/O and you probably don't want to lose 10% to 40% of your processors to calculating RAID 5 data and location. This is a job best suited to a dedicated disk array.

[John Payne_2]

As far as getting MirrorDisk/UX reinstalled, the software is found on the HPUX applications CD's. Unfortunately for you, they are locked unless you have a codeword. When you purchase the license, they send you a customer ID so you can request the codeword.

Do you have any documentation with the server that lists codewords or anything like that? Or I guess, does the customer? Usually you can get HP to help if there is a software support contract with the machine.

I hope that makes sense to you. If not, it can be explained in much greater detail...

Hope it helps

John

[Trond Haugen]

As there is Mirror/UX on the 10.20 you could split the mirror before the re-installation just to have a fallback in case the installation fails. A Ignite tape is another option.

Regards,
Trond

[John Carr_2]

Hi

with regards to the license check to see if the mirror disk depot has been copied onto the present system. If it has been copied on and unlocked you can simply back it up to tape , then restore it on new system , then install it again without need for key.


If you use Clay's script add these lines to the end

-------------------------------------

# Update the boot info contained in the BDRA for the mirror copies of the boot, root and primary swap.

/usr/sbin/lvlnboot -b /dev/vg00/lvol1
/usr/sbin/lvlnboot -v -r /dev/vg00/lvol3
/usr/sbin/lvlnboot -s /dev/vg00/lvol2
# Check if the BDRA is correct

/usr/sbin/lvlnboot -R /dev/vg00

# verify the mirrors were properly created

lvlnboot -v

-------------------------------------------

you can find some good documentation in the "Building an HA Cluster configuration guide" chapter 5 page 6&7.



cheers
John.

[Matt Harrell]

What incredible feedback! Thanks to everyone for the help. This is going to be quite a daunting task. Fortunately, they have a backup server there that I will be switching their Progress database to while I work on the main server. It is much slower, though.