SAN Sizing and how to plan proper IOPS size?

[JESX35]

Hello All,

Just wondering what everyone is using to judge IOPS for your virutal enviroment prior to implementing or upgrading their SAN.  For Example say you have a general enviroment virutalized in Vmware 4.1 as such:

AD Server (Secondary)

SQL 2008 64 bit Server

Terminal Server 2008 R2 x4

Windows Server 2008 R2 File server

1 or 2 Windows Server 2003 application servers (Print server line of buisness apps)

Exchange 2010 Server

Now I have found lots of information on Exchange and the other odd application on what it requires for IOPS and planning tools to use for these apps but I can't seem to find any good tools or information for the enviroment on a whole.  So what about the IOPS required for all the other servers in the virtual enviroment.  What is the best practice when planning this out.

[amvmware · Accepted solution]

Utilise the information from assessment tools such as VMware CP or Platespin PowerRecon or similar. You can also use logical disk performace counters if  looking at Windows servers. Some SAN's provide consoles that show the current IO load.

I would not take manufacturer figures at face value - they are designed to look good. You need to understand your environment and IO requirements and what requirements you have of a new SAN  - ie what additional loads you intend to deploy.

[dquintana]

Here you can find a IOPS Calculator  that sure helps you .

http://www.wmarow.com/strcalc/

Diego

[STJ201110141]

Hello,

Out of curiosity how did you go with your SAN, I am trying to set up nearly an identical configuration and trying to work out the IOPS.

[cditmo]

I'm also very interested to hear the outcome of his new SAN selection; how were the required IOPS determined?

[JESX35]

Hello,

Sorry for the long delay

We ended up using a couple different tools.  We used perfomon counters for disk IO meters on the psyhical server along with IO Meter which is free software you can download that lets you track IO with many different settings.  Once we got the numbers we knew we where going with a Dell Equallogic SAN solution so we talked to the pre-sales rep to get the hard numbers on the SAN.  The Equallogic's we where looking at had 16 SATA disks and in a RAID 10 each Equallogic would have around 900-1100 IOPS.  With all our numbers back from perfmon and IO Meter we knew we needed around 1500 IOPS.  So to give us some growth we went with 2 Dell Equalloics which gave us 2200 IOPS.

Many SAN vendors also have tools you can download for free and use to get your IOPS information before a purchase or upgrade.  Also many of the SAN vendors also have data sheets that give you some ruff numbers on what typical servers will use for IOPS for ex. Exchange 2010 server with 5000 users would use 1200 IOPS.

Since the post I also went through the Vmware Design course and asked this very question.  The response was Perfmon, IO Meter, and tools used by the SAN vendors.  Hope this helps

[JESX35]

IBM also uses a licensed version of software called Disk magic which is really good for IOPS sizing however if you don't want to purchase the licensed version there is an end user license version as well.  Here is some extra reading information on it:

http://www.intellimagic.net/intellimagic/products/intellimagic-direction

[cditmo]

JESX35,  Wow, that was a quick reply! I'm happy to hear that you found success in determining your IOPS requirements. Thanks so much for the information and advice. One last update; I found the following link regarding best practices for LUN sizing on the communities forum:  http://communities.vmware.com/docs/DOC-10990   Best of luck and thanks again!

[CloudViseSoluti]

Dell Performance Analysis Collection (DPACK) beta gui based easy to use collection. Collect stats for whatever period you want and upload file to Dell, 1 hour later you get a detailed report of each server, IOPs, Reads/Write size, CPU Memory, Peaks etc etc..

Very good tool to understand your IO workload profile.