RAID 1+0 Question

[Curtis Schiewek]

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

[Jeff Schussele]

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

[baiju_3]

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

You may have to go for Veritas in this case .


Thanks,
BL.

[Steven E. Protter]

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

[John Waller]

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.

[Curtis Schiewek]

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?

[Alzhy]

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.

[Devender Khatana]

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