topic Re: Adding disks to Nike array in Disk Enclosures

Adding disks to Nike array

Kevin Gammons — Mon, 25 Feb 2002 13:13:20 GMT

We have a Nike 20 disk array. Presently there are 10 4.2 G drives. We have 7 of the drives in one Raid 5 array and the other 3 drives in another Raid 5 array. The larger array is used for production purposes, the smaller for development (each assigned to a separate SP).
I'm in the market for additional disk space for both systems and have thought about purchasing 10 8.8 G drives. I'm under the impression that if I try to add the larger capacity drives to the existing volume groups, I'll will not be able to use the full disk capacity. Is this true?
If so, can I simply create new volume groups and bind them to the SP? I suppose my real question is this, Can I bind multiple volume groups same SP (even if the volume groups are comprised of differnet sized physical disks)?
Any assistance would be appreciated.

Re: Adding disks to Nike array

Insu Kim — Mon, 25 Feb 2002 14:39:23 GMT

From the Nike disk array manual,
If disk modules with different capacities are mixed in a logical disk unit, all of disk modules will act as though they match the capacity of the lowest capacity disk module and performance will degrade.

Click on " http://h200002.www2.hp.com/bc/docs/support/SupportManual/lpg28392/lpg28392.pdf" for the details.

Hope this helps,

Re: Adding disks to Nike array

Bill McNAMARA_1 — Mon, 25 Feb 2002 15:43:26 GMT

Insu is correct. It is a good idea that all disks on a nike lun be the same manufacturer/ size and FW revision.

Don't mix IBM and Seagate mechs either. It will work, but perf will suffer because of different block sizes.

Don't replace disks offline either or you'll end up with an unbootable array.

Label the disks before removing them.

Later,
Bill

Re: Adding disks to Nike array

Vincent Farrugia — Tue, 26 Feb 2002 15:12:47 GMT

Hello,

Add same disk size and same manufacturer preferably. Actually, different sized disks in same lun is not supported as far as I know.

HTH,
Vince

Re: Adding disks to Nike array

Kevin Gammons — Tue, 26 Feb 2002 15:29:03 GMT

Thanks for the information