topic Re: Mirroring root on Itanium in Operating System - HP-UX

Mirroring root on Itanium

Scott Buffington — Wed, 06 Apr 2011 12:34:30 GMT

Is this the correct documentation for mirroring root on Itanium?
http://h21007.www2.hp.com/portal/site/dspp/menuitem.863c3e4cbcdc3f3515b49c10
8973a801/?ciid=00089099cee021109099cee02110275d6e10RCRD

I have a ia64 hp server rx6600 and I am guessing I screwed up mirroring because I am unable to set an alternate boot path with setboot. Previously I only worked with RISC and 11.11 and 11.23 and want to make sure I have the right documentation. I used an old method and found some threads stating Itanium uses a new method. However, I am encountering broken links in the threads, so I apologize for reposting question.

# lvlnboot -v
Boot Definitions for Volume Group /dev/vg00:
Physical Volumes belonging in Root Volume Group:
/dev/disk/disk10_p2 -- Boot Disk
/dev/dsk/c0t0d0 -- Boot Disk
Boot: lvol1 on: /dev/disk/disk10_p2
/dev/dsk/c0t0d0
Root: lvol3 on: /dev/disk/disk10_p2
/dev/dsk/c0t0d0
Swap: lvol2 on: /dev/disk/disk10_p2
/dev/dsk/c0t0d0
Dump: lvol2 on: /dev/disk/disk10_p2, 0

I guess I can just break the mirror and start again? Thank you.

Re: Mirroring root on Itanium

melvyn burnard — Wed, 06 Apr 2011 12:42:24 GMT

This is documented in the HP-UX System Administrator's Guide: Logical
Volume Management
HP-UX 11i Version 3

But I attach the part you need in a word document

Re: Mirroring root on Itanium

Torsten. — Wed, 06 Apr 2011 12:44:31 GMT

You can use the appendix from here:

When_Good_Disks_Go_Bad_WP
http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c01911837/c01911837.pdf

Re: Mirroring root on Itanium

Torsten. — Wed, 06 Apr 2011 12:48:45 GMT

Better to use hardware mirroring on this server anyway!

If you have the default SAS controller, you can have 2 pairs of hardware mirrored disks.

Re: Mirroring root on Itanium

Scott Buffington — Wed, 06 Apr 2011 16:58:29 GMT

I am investigating all the replies. The hardware mirroring was something I was not aware of but I see it mentioned a lot in other posts. I am checking into that but I want to know how to do the standard mirroring.

Running into an issue though, after entering this command

insf -e -H 0/4/2/0.0.0.0.0

For my disk, I do not see the see the partions under /dev/rdisk, I do see slices were created for the disk in /dev/rdsk. So when I try the next step, pvcreate I get an error that there is no such file or directory.

# pvcreate -B /dev/rdisk/disk11_p2
Couldn't stat physical volume "/dev/rdisk/disk11_p2":
pvcreate: Couldn't open physical volume "/dev/rdisk/disk11_p2":
No such file or directory

More info:

# ioscan -fnC disk
Class I H/W Path Driver S/W State H/W Type Description
=====================================================================
disk 0 0/4/2/0.0.0.0.0 sdisk CLAIMED DEVICE HP EH0146FARWD
/dev/dsk/c0t0d0 /dev/dsk/c0t0d0s2 /dev/rdsk/c0t0d0 /dev/rdsk/c0t0d0s2
/dev/dsk/c0t0d0s1 /dev/dsk/c0t0d0s3 /dev/rdsk/c0t0d0s1 /dev/rdsk/c0t0d0s3
disk 1 0/4/2/0.0.0.1.0 sdisk CLAIMED DEVICE HP EH0146FARWD
/dev/dsk/c0t1d0 /dev/dsk/c0t1d0s2 /dev/rdsk/c0t1d0 /dev/rdsk/c0t1d0s2
/dev/dsk/c0t1d0s1 /dev/dsk/c0t1d0s3 /dev/rdsk/c0t1d0s1 /dev/rdsk/c0t1d0s3

# ioscan -m dsf
Persistent DSF Legacy DSF(s)
========================================
/dev/rdisk/disk10 /dev/rdsk/c0t1d0
/dev/rdisk/disk10_p1 /dev/rdsk/c0t1d0s1
/dev/rdisk/disk10_p2 /dev/rdsk/c0t1d0s2
/dev/rdisk/disk10_p3 /dev/rdsk/c0t1d0s3
/dev/rdisk/disk11 /dev/rdsk/c0t0d0

Re: Mirroring root on Itanium

Torsten. — Wed, 06 Apr 2011 17:08:03 GMT

I usually do a

# insf -eC disk

and it works for me.

Regarding the hardware mirror:

When replacing a hardware mirrored disk, you just swap the disk - that's all.

Replacing a LVM mirrored SAS connected disk could be a real pain - a lot of commands are needed.

Re: Mirroring root on Itanium

Patrick Wallek — Wed, 06 Apr 2011 17:08:25 GMT

Try using the legacy device files with the mirroring. Those should still work.

So, with your pvcreate do:

pvcreate -B /def/rdsk/c0t0d0s2

Re: Mirroring root on Itanium

Scott Buffington — Wed, 06 Apr 2011 17:25:49 GMT

I have looked at sasmgr. Is there a sasmgr bible somewhere, sort of like the document included above?

I guess the issue I run into a lot that I find these forum posts, but the links are always broken, or seem to be. Very frustrating. I am not at all familiar with sasmgr other than the man page and what info I found on the forum. Is the man page the place to look? Meaning does the man page have everything I need to know to do hardware mirroring?

I am right obviously right at the start of setting this server up and would like certainly like to pursue the best method. It sounds like hardware mirroring with this hardware is the way to go.

Re: Mirroring root on Itanium

Torsten. — Wed, 06 Apr 2011 17:46:05 GMT

Google will help you to find

"HP 8 Internal Port SAS Controller and HP
Multi-Port Internal SAS Controller Support
Guide"

BTW, I think running insf against the legacy H/W path will only create legacy device files - never tried.

I would do hardware mirroring for the boot disks - be aware, data will be lost while creating the RAID.

Re: Mirroring root on Itanium

Torsten. — Wed, 06 Apr 2011 17:48:10 GMT

http://h20000.www2.hp.com/bc/docs/support/SupportManual/c02017117/c02017117.pdf