Home > EMC, Linux > How to calculate IOPs for your storage

How to calculate IOPs for your storage

Use the following for per drive calculations:
7200 RPM drive = 75 IOPS
10k RPM drive = 125 IOPS
15k RPM drive = 175 IOPS

Use this as an example:
This is based on my calculations for 16 disks, RAID5:
What is required for large scale:
15k FC drives = ~ 200 IOPs each
READ/WRITE profile % = 30% Read / 70% Write
n = (%R + f (%W))(tps)/200 (n = min. # of disks needed, f=1 for RAID0, f=2 for RAID1 or RAID10, f=4 for RAID5, f=6 for RAID6)

In this case, if we require 5000 IOPS, it would take 78 RAID5 disks to fulfill.
(0.3+4(0.7))(1500 + 3500)/200 = 78 disks

Categories: EMC, Linux
  1. mulle78
    May 2, 2012 at 12:46 pm

    Thanks for this articly, but why I have to multiplicate the overhead by write performance with 4 for raid 5

    • May 2, 2012 at 4:40 pm

      Because RAID5 is worse for writes than a RAID0, which is what the formula is based on. This applies a factor to the equation to account for the poorer performance of the RAID5. Hope that answers your question.

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