topic Re: create a Disk group 4D+4D into xp24k in Disk Enclosures

create a Disk group 4D+4D into xp24k

bouazzaoui — Thu, 12 Feb 2009 14:38:28 GMT

hello Gourous,
I'm trying to install a new XP and I want to create a Disk group 4D+4D but without using concatenation
is there any way to do that
I can reinitialize the XP because there is no data on it
thank you for your help

Re: create a Disk group 4D+4D into xp24k

IBaltay — Thu, 12 Feb 2009 15:27:43 GMT

Hi,
4D+4D is 2 concatenation of 2D+2D
so it cannot be done without the concatenation,
but it is highly reliable, because it consists from 4 RAID pairs... and it is better in performance than 2D+2D

Re: create a Disk group 4D+4D into xp24k

Nigel Poulton — Thu, 12 Feb 2009 16:06:36 GMT

Just to be clear, I get this a lot so want to make sure you understand. The term "concatenation" is used by the XP software (SVP and Remote Console etc) but it is not a concatenation! It is a stripe across 4 RAID pairs as IBalty has mentioned.

The stripe size for 2+2 is 1024K
The stripe size for 4+4 is 2048K

The term concatenation is misleading and should probably be changed, but normally it is HP or HDS engineers that create the RAID Groups and they "know" about this.

So create it with concatenation.

Nigel

Re: create a Disk group 4D+4D into xp24k

Nigel Poulton — Fri, 13 Feb 2009 09:55:35 GMT

In case anybody is interested in some info re RAID1 (4+4) versus (RAID1 (2+2) on an XP12000 and XP24000 and if its a concat or a stripe etc, Ive put a post up here that covers off the topic -

http://blogs.rupturedmonkey.com/?p=211

Re: create a Disk group 4D+4D into xp24k

bouazzaoui — Fri, 13 Feb 2009 11:00:20 GMT

dear all,
thank you all for the good information you provide me
I will now close this thread for now
regards,