topic Striping on XP512 in Disk Enclosures

Striping on XP512

Stephen Young_1 — Wed, 31 Oct 2001 16:43:06 GMT

Can anyone tell me if/how RAID 0/1 works on
as XP512 array and how to set it up ?

Re: Striping on XP512

Sanjay_6 — Wed, 31 Oct 2001 17:17:26 GMT

Hi Stephen,

Here is a thread to the manuals for xp512
http://www.hp.com/cposupport/manindex/hpsurestor21443_eng_man.html

Hope this helps.

thanks

Re: Striping on XP512

Vincent Fleming — Sat, 03 Nov 2001 15:32:11 GMT

Hi;

Yes, RAID 0/1 works on the XP512. You may or may not know this, but it does RAID 0/1 internally.

Here's how it works: Array Groups (groups of 4 drives - you purchase them this way) are formatted, and made into two mirror pairs. The LDEVs, when created, are striped across the two mirror pairs - giving you a 4-drive RAID 0/1 configuration.

You may stripe over LDEVs that are on different array groups (via software - LVM, Veritas VM) to increase the number of disks in the stripe set - software stripe over 4 LDEVs that are on different array groups and you'll be using 16 drives. It's very common to stripe over 10-20 array groups.

That's how to set it up with software striping... if you were referring to setting the array itself up to do RAID 0/1 (ie: change the RAID level on an existing array group or as part of installing a new array group), well, you should have this done by HP - that must be done from the service console, which you're not supposed to be mucking with.

Good luck

Re: Striping on XP512

Insu Kim — Sun, 04 Nov 2001 11:56:51 GMT

Hello

If you had a storage experience like NIKE, AutoRAID, FC60 and so on, it would be the first thing to decide that you first bind a group of disks to a RAID type.

You will be given a choice of RAID5, RAID1, RAID1/0, RAID 0, Independent disk when you bind a bunch of disks.

In XP disk array,
There're only two RAID levels supported, RAID5 and RAID1 but RAID1 in XP512 has been changed to include striping of the data blocks and then mirroring, that is, RAID 1/0.
What I'm trying to say is that RAID1 in XP512 is the same as RAID 1/0 in other storage documentations.

As vincent in the previous posting wrote, you can use software to increse the number of disk in the stripe set that are on a different domain for better performance.
(Each domain is connected to an DKA pair and controls one RAID type, RAID-1 or RAID5.)

The RAID level can be configured by SVP (Service Processor) seated in the middle of DKC and this can be done by HP qualified service people only.

Hope this helps,