topic Re: Disk mirroring in Operating System - HP-UX

Disk mirroring

Mark MacDonald_4 — Tue, 04 Oct 2005 07:17:12 GMT

We currently have four 36GB hard drives installed on an HP-UX 11.0 system. Two are grouped into the root vg (vg00) and the other two are intended to be a mirror for that vg. When I run the third party script which uses the HP mirroring software, it fails saying that the vg is 72GB and I only have two 36GB drives available. I have placed the two drives into their own volume group, and it still does not see them as one 72GB drive.

Can someone tell me what I might be doing wrong? Thank you much.

Re: Disk mirroring

Luk Vandenbussche — Tue, 04 Oct 2005 07:19:22 GMT

Can you send us the script and the output of

=> vgdisplay -v vg00
=> vgdisplay -v vg01

In attachment a working script

Re: Disk mirroring

MarkSyder — Tue, 04 Oct 2005 07:19:31 GMT

You need to extend vg00 so it contains all four discs.

Mark Syder (like the drink but spelt different)

Re: Disk mirroring

RAC_1 — Tue, 04 Oct 2005 07:20:13 GMT

vgdisplay -v vg00
Do you have all four disks in vg00??

Also what is the pe settings for vg??

Re: Disk mirroring

Robert-Jan Goossens — Tue, 04 Oct 2005 07:20:20 GMT

Hi,

Could you post an

# ioscan -fnCdisk

Regards,
Robert-Jan

Re: Disk mirroring

DCE — Tue, 04 Oct 2005 07:33:06 GMT

Mark,

In order to mirror with e the HP mirroring product, all the disks need to in the same volume group. You cannot mirror one VG to another.

Remove the non vg00 vg and add the disks to vg00.

Be sure to run pvcreate -b against the mirror boot disk before you add it to the vg in order to make the mirror bootable.

Re: Disk mirroring

Mark MacDonald_4 — Tue, 04 Oct 2005 07:35:06 GMT

I wish I could give everyone the output they ask for as it would make things easier, but the HP box is in a different area on a different network with no way to transfer files.

What I'm understanding from your questions is that all four disks need to be in vg00, in which case I would just extend it. I guess I don't properly understand the process.

I figured that if I wanted to mirror vg00, the destination disks would need to be outside vg00. Is that not the case?

Re: Disk mirroring

MarkSyder — Tue, 04 Oct 2005 07:37:39 GMT

No - the mirrored volumes need to be in the same vg.

Mark

Re: Disk mirroring

Dave Hutton — Tue, 04 Oct 2005 07:42:24 GMT

vgextend /dev/vgXX /dev/dsk/cXtXdX /dev/dsk/cXtXdX

Then you can mirror them. lvextend -m 1 /dev/vgXX/lvolX /dev/dsk/cXtXdX /dev/dsk/cXtXdX

No need to transfer files, does your terminal emulator have a buffer? or can you cut and paste?

Re: Disk mirroring

Bob_Vance — Tue, 04 Oct 2005 07:58:12 GMT

Luk,

I may be hallucinating, but it appears to me that the script has a bug in it %~/

...
#set -x
echo "Mirroring root disk to $DEV"
echo "Do you want to proceed (y/n) [n] ? \c"
read answer
...
DEV=$1
RDEV=$(echo $DEV|sed 's/dsk/rdsk/')

It asks if you want to mirror to $DEV *before* it sets $DEV to $1

I also notice that it *assumes* that the user put in a non-raw device name. I would check for that and exit if not :

if ! echo $DEV | grep /rdsk/ > /dev/null ; then
echo you must enter raw device name -$DEV- is not raw.
exit 1
fi

(or you could allow him to enter either type and fix it in the script)

bv