topic RAID 1+0 Question in Operating System - HP-UX

RAID 1+0 Question

Curtis Schiewek — Tue, 27 Sep 2005 13:35:27 GMT

I've been searching far and wide for insight on how to create a RAID 1+0 (a stripe set of 3 mirrored pairs in my case) array on HP-UX 11i. I've managed to create RAID 0+1 arrays but I can't wrap my head around doing a RAID 1+0. Can it be done with LVM or is VxVM required? How exactly would it be accomplished?

Thank you,

Curtis

Re: RAID 1+0 Question

Jeff Schussele — Tue, 27 Sep 2005 13:45:08 GMT

Hi Curtis,

Can't do RAID 1+0 with either LVM or the base VxVM.
You'll need the full-blown VxVM to do that.

HTH,
Jeff

Re: RAID 1+0 Question

baiju_3 — Tue, 27 Sep 2005 14:03:44 GMT

Yes , HP LVM does not support RAID 1+0 .

You may have to go for Veritas in this case .

Thanks,
BL.

Re: RAID 1+0 Question

Steven E. Protter — Tue, 27 Sep 2005 14:18:43 GMT

You can kind of do an fake raid with lvm by using a script to create and then extend lvm areas rotating across a number of disks. Then you can use mirror/ux to make a mirror copy of that.

I'm not sure you will be pleased with the results and peformance.

On paper there really is no build in way of doing striping with LVM. You kind of have to play around.

You are better off performance wise, especially in a heavy write environment to use mirror/ux and go straight raid 1.

SEP

Re: RAID 1+0 Question

John Waller — Wed, 28 Sep 2005 02:15:52 GMT

When I wish to create a striped mirrored Volume group and lvols I use the following which I found somewhere on the forum a few years back.

# vgcreate -g PVG1 /dev/vg01 /dev/dsk/c0t0d0 /dev/dsk/c0t1d0 /dev/dsk/c0t2d0

# vgextend -g PVG2 /dev/vg01 /dev/dsk/c1t0d0 /dev/dsk/c1t1d0 /dev/dsk/c1t1d0

# lvcreate -D y -s g -m 1 -l 120 /dev/vg00

This will create a 960Mb striped mirrored lvol assuming an 8Mb extent size.

Re: RAID 1+0 Question

Curtis Schiewek — Mon, 03 Oct 2005 09:58:10 GMT

It's as I feared, it can not be done (at least not properly). So other then getting the full blown Veritas Storage product, what are my choices for RAID 1+0. I currently have 2 TachyonXL based FC cards connecting to a ds2405 . Is there a such thing as FC cards with hardware raid?

Re: RAID 1+0 Question

Alzhy — Mon, 03 Oct 2005 12:17:21 GMT

Your only software solution is a full license of VxVM period.

Since your Disk encosure is FC one, there is currently no RAID card available. All HW based RAID card implementations are SCSI based.

Re: RAID 1+0 Question

Devender Khatana — Mon, 03 Oct 2005 23:24:11 GMT

Hi,

Moreover, there is also no possibility that we will see FC based raid cards in future, as most of the FC based arrays provide raid within themselves which do not leave the option to have a FC based RAID card used.

HTH,
Devender