topic Re: EVA6000 I/O calculation in Disk Enclosures

EVA6000 I/O calculation

Hasan_9 — Mon, 09 Jan 2006 13:20:39 GMT

Hello Everybody,
I want to calculate I/O bandwidth of my disk array. It is an EVA 6000 with 28 disks.
I found the following link in regards of my question. In the below link Uwe, offer a formula:
I/O bandwidth / number of disk / chunk size =IOPS
They talked about an EVA 4000.
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=977114
Now, I want to calculate maximum I/O bandwidth of my EVA with that formula. However I do not know what chunk size is and how much IOPS each 15rpm disk has.
Please advice.

Re: EVA6000 I/O calculation

Ivan Ferreira — Mon, 09 Jan 2006 14:52:54 GMT

EVAs uses fixed 256k chunk size, but I don't know if that formula will give you the real IOPS that the EVA will perform. For the I/O bandwidth, check the eva quickspecs.

Re: EVA6000 I/O calculation

Uwe Zessin — Mon, 09 Jan 2006 15:34:36 GMT

The EVA6000 uses the same controller (HSV200) like the EVA4000 - the controller does not know if it is working in an EVA4000 or 6000 ;-)

The EVA3000/5000 use a chunk size of 128 KBytes - my guess is that the 4000/6000/8000 use the same size.

The formular only makes sense for large sequential transfers - random I/Os with large seek distances will kill result in smaller MB/s throughput.

Re: EVA6000 I/O calculation

Ivan Ferreira — Mon, 09 Jan 2006 15:47:17 GMT

Uwe is right, my mistake, The chunk size is 128KB (256 blocks), fixed.

Re: EVA6000 I/O calculation

Hasan_9 — Mon, 09 Jan 2006 23:43:40 GMT

Thank you all,
How much IOPS does a single 15K disk has? What about 10k disk?What can be the maximum IOPS of a disk?

Re: EVA6000 I/O calculation

Pat Obrien_1 — Wed, 11 Jan 2006 12:10:17 GMT

I have multiple EVA5K, and can consistently get 500MB/second on some of these. It seems to be a never ending battle to break 520MB/s and to keep this level of performance from multiple EVA's consecutively. Usually get 1 at 480 and another at 510, with a 3rd at 350, and others hardly reporting any. relocate, rerun, and still get hot spots, though I can move from one to another. Still working with dba to tune.