topic Re: LSM RAID 1+0 Possible? in Operating System - Tru64 Unix

LSM RAID 1+0 Possible?

Mario Stargard — Tue, 14 Dec 2004 11:44:30 GMT

Is it possible to create a RAID 1+0 configuration using only LSM on Tru64 5.1b? The docs say LSM does 0, 1, 0+1, and 5 but are silent about 1+0.

I didn't find anything on Google about RAID 1+0.

Thanks.

Mario

Re: LSM RAID 1+0 Possible?

Michael Schulte zur Sur — Tue, 14 Dec 2004 12:33:28 GMT

Hi,

yes, it is possible. You build two plexes with 3 striped disks and these plexes you mirror. You find it in the docs for lsm page 4-16.

greetings,

Michael

Re: LSM RAID 1+0 Possible?

Mario Stargard — Tue, 14 Dec 2004 14:06:40 GMT

Thanks, Michael. Unless I'm mistaken, page 4-16 of the LSM manual shows how to make RAID 0+1 volumes. That is, mirroring two stripes. I'm looking to do the inverse, striping across mirrors.

Mario

Re: LSM RAID 1+0 Possible?

Michael Schulte zur Sur — Tue, 14 Dec 2004 14:46:25 GMT

Hi Mario,

yes, you are right. I overlooked that detail. It seems not possible because you have only striped or concatenated plexes and not a mirrored one. The top layer is always the mirror.

greetings,

Michael

Re: LSM RAID 1+0 Possible?

Johan Brusche — Tue, 14 Dec 2004 18:50:40 GMT

What issue are you want to address here ?
If intention is to increase the size of the mirrored volume, you could try "volassist grow"

__ Johan.

Re: LSM RAID 1+0 Possible?

Han Pilmeyer — Wed, 15 Dec 2004 06:40:25 GMT

I suspect it's the availability issue of 1+0 versus 0+1.

Unfortunately this can not be done with LSM.

Re: LSM RAID 1+0 Possible?

Mario Stargard — Wed, 15 Dec 2004 09:58:52 GMT

Can't be done. Thanks everyone.