Mixing drive speeds in array for Proliant 6000

[CA1224642]

Hi Everyone. I had a quick look to see if this had already been answered, but I couldn't find anything... I have some 9.1Gb 7,200RPM drives in my array, and some 10,000RPM drives I'd like to use. My question is, can I mix the two drive speeds in the same array without any consequences other than a loss of performance from the 10K drives? The array controller is a 3100ES. All drives have the same capacity and are all Wide/Ultra drives. Thanks, Bruce

[Steven Clementi]

The 10k drives, i believe, will still operate at 10k since rotational speed is not prt of the SCSI protocal.


On the other hand, if you had U160 drives that were 7.2k and U320 drives that were 10k, all the drives should operate at U160 speeds, but again... the rotational speed should not make any difference.

The performance would still be bast on how fast the 7200 drives can go and the 10k drives would have no problem keeping up.

Someone PLEASE correct me if I am wrong. (or let us know if I am right)


Steven

[Mike Stevens_2]

In my experience of trying this it was a bad idea. If you listen to the faster drives, it sounds like they are skipping a beat to slow down to the speed at which the 7200 rpm drives are running. In theory, it would be reasonable to think this would work, but from personal experience and also from talking to some people in the drive business, they and I also, recommend against mixing drive speeds. Your best and most reliable arrays will have drives of the same rotational speed and access times. This will keep all of the drives running at their peak and your data moving at its peak.

Hope this makes sense,

Mike Stevens

[CA1224642]

Hi All,

Okay, two conflicting answers...

I could assign all the 10k drives to one SCSI bus and create a seperate logical drive from all the 7.2k drives, but that sort of defeats my intended purpose of having ONE RAID 5 drive utilising ALL drives.

Can anyone give me a definitive answer?

Thanks,

Bruce

[marco lemmers]

i have had the same question and the answer i got was. NEVER MIX DIFFERENT DRIVES

in a raid config allways use drives that are the same at any time.
it works better and it keeps your drives alive for a long time