P2000 Performance Calculator

[MrMagicTX]

Hello,

Is there some kind of calculator which would allow me to calculate performance of a P2000 with different disk types. We are about to get few of those for different uses and it would be nice to be able to calculate what I can pull out of those devices.

Thank you for you help!

[PAC-MAN]

HI there,

http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareDescription.jsp?lang=en&cc=us&prodTypeId=12169&prodSeriesId=4118559&prodNameId=4310834&swEnvOID=2002&swLang=8&mode=2&taskId=135&swItem=MTX-5e878f833e2c4d078c0e8368bd

Install the P2000 Performance monitoring tool on the host, this software will pull all sort of performance data.

I havnt heard of any calculator but using this tool you can pull individual reports for different drive configuration on the array.

[David_Schwartzs]

You should probably consult with a HP Storage Specialist partner to get a more exact answer, but here's some general guidance.

There's three general principles you need to consider -

1. Chassis Bandwidth

2. Disk Bandwidth

3. Disk IOPS

Chassis Bandwidth is how fast the chassis can send and receive data.  While there are numerous factors that can affect the aggregate bandwidth potential - what RAID level is chosen, how efficient the controller is at calculating parity (if necessary), number of drives and shelves being managed, number of LUNs and attached hosts - the most basic consideration is interface.  Using the wrong interface can be a serious bottleneck. Consider that whatever connectivity you choose for the chassis is your ultimate transfer throughput bandwidth speed limit.

Disk Bandwidthis how fast the individual disks (and disks as a RAID set) can perform.  Even though the drive controllers are capable of 6Gb/s of bandwidth, a spinning 15K disk peaks at about 200MB/s (roughly 1.6Gb/s).  If you were using RAID 0, your throughput would be roughly the total combined speed of the drives - in a 24 drive array, you could expect 3600-4800 MB/s of available drive bandwidth.  That being said, keep in mind that a single chassis connection on 8Gb fibre is only about 1000MB/s of bandwidth.  Which brings me to my next point...

Disk IOPS is the number of different input/output commands the drive can respond to per second.  A 7200 rpm SATA drive typically performs in the 50-80 IOPS range, and can peak as high at 150 IOPs; 15K RPM SAS drives typically perform in the 170-210 IOPs range, and can peak as high as 400 IOPs.  If you have a lot of varied applications and workloads, or lots of very small transactions, occurring, IOPS is even more important than bandwidth.  At a certain point, because of the chassis connection speed limit, adding drives can no longer add additional transfer throughput bandwidth, but additional drives can aid with increasing aggregate IOPS performance.

In summary -

If you're doing a large number of transactions and multiple workloads, you need larger number of higher RPM drives to achieve higher IOPs.  The connection type of your chassis that you choose will depend on the actual amount of data in those transactions that you need to transfer. (i.e. a large number of transactions that are small, less than 1MB in size, may not even exceed 1Gb iSCSI performance.)

If you're doing primarily large file size data transfers and few transactions, you need more bandwidth and I'd strongly recommend avoiding 1Gb iSCSI.  Type of drives really won't matter, but if you choose lower rotation SATA or midline SAS drives you'll need more of them to saturate the pipe.

Hopefully that somewhat answers your question.