Guidelines when using IOmeter to measure disk performance

Iometer is an I/O subsystem measurement and characterization tool for single and clustered systems. It was originally developed by the Intel Corporation and in 2001 it was given to the Open Source Development Lab (OSDL). Since the moment of birth it gained in popularity and basically every IT guy has used it at least once.

IOmeter is a very powerfull tool, but if it’s inproperly used it will give you some distorted results. Therefore it’s advised to follow these guidelines:

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Measuring HP EVA performance

Sometimes customers ask me to define the performance of the storage array. In my case these are mainly HP EVA and MSA boxes. Each time I explain them that measuring performance is one of the most difficult tasks for us as storage engineers.

Everything depends on the configuration, the use and allocation of the storage box.

  • What type of disks are added in the storage array? What’s the size, RPM and amount of disks?
  • What is the maximum responstime for a vdisk?
  • What’s the type of IO and IO sizes that are committed on the storage array?
  • What is the combination of read- and writes on the box?
  • In what (v)Raid level are the disks defined?
  • And so on..

I will try to share a bit of my knowledge and experience allowing you to get a brief idea of the performance of an Enterprise Virtual Array.
The information below can be used as a guideline for configuring an HP EVA Performance Advisor. Once again, please note that the performance numbers indicated here can differ for your environment. If you really want to get a clear look into the performance of your system, please consult your HP representative and/or partner to schedule an EVA Performance Assessment.

Below is a description of my personal understanding and configuration for the storage box.
Each time a HP P6000 Performance Data Collector output is added to ease the understanding.
The performance numbers were collected during backup window.

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