Link to home
Start Free TrialLog in
Avatar of Tim OBrien
Tim OBrien

asked on

Determine IOPS

My boss asked that I determine the current IOPS on a server and recommend alternative solution.

He doesn't need specific metrics just a general idea of current iops and what new server should be able to handle the current needs.

From what I am reading I keep getting these extremely detailed breakdowns of number. I have used perfmon to collect the metrics per a website which  I thought could give me this information. I am now staring at the numbers but have no idea what to do with them. I assumed there was a general formula I could use based on my collections but I don't know what to do. Any suggestions would be help. Please see attached file of what I have and if anything else if need. Again I just need a general idea of the IOPS as this is not a mission critical server. Basic understandable explanation would be great. Thanks.
Perfmon.jpg
Avatar of Calvin Paxson
Calvin Paxson

From a cursory glance it looks like you are using 57 IOPS.  From wikipedia:

7,200 rpm SATA drives      HDD      ~75-100 IOPS[2]      SATA 3 Gbit/s      
10,000 rpm SATA drives      HDD      ~125-150 IOPS[2]      SATA 3 Gbit/s      
10,000 rpm SAS drives      HDD      ~140 IOPS[2]      SAS      
15,000 rpm SAS drives      HDD      ~175-210 IOPS[2]      SAS      

Realistically you want to get an average over time:

http://blog.synology.com/blog/?p=2086 

and then use the above chart to determine how many disks you need at max.  There is a penalty for IOPS when you are using RAID.
Avatar of Tim OBrien

ASKER

Could you let me know which metrics you referred to when determining that number? I am fairly certain the metrics I provided were an average over 1 day which would be enough time to get good numbers.

Reading the documentation of what configuration I may need for the new server was more understandable. My main issue was filtering thru the values I provided and determining current IOPS. Thanks for your initial help!
DiskWrites/sec
DiskReads/sec
DiskTransfers/sec

Those should be the values you are interested in.  My math was bad but i'm sure you've already corrected it!
I don't expect you to do all the work. I will review those numbers and hopefully figure it out. Thanks so much!

I will review the numbers and mark it as a solution shortly, don't know if it closes out question  if I mark as solution now so will hold off.
Ok I added up the numbers and came to about 105 IOPS
DiskReads/sec - 4.6
DiskTrasnfers/sec  - 57.6
DiskWrites/sec - 53

105 IOPS is the limit this server can handle, from what I understand this doesn't indicate what the the new server should be planned for as this 105 IOPS is again the current limit of the server.

I read that referring to the Current Disk Queue Length will provide an indication to how much IOPS I should plan for so somehow the Total IOPS of 105 and the Current Disk Queue Length Metric of 8.9 will indicate how many IOPS I should plan for but I don't understand how the Current Disk Queue Length should be applied when forecasting.
ASKER CERTIFIED SOLUTION
Avatar of Calvin Paxson
Calvin Paxson

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Thanks for your feedback.