VMware IO Analyzer

VMware I/O Analyzer is an integrated framework designed to measure storage performance in a virtualenvironment and to help diagnose storage performance concerns. I/O Analyzer, supplied as an easy-to-deployvirtual appliance, automates storage performance analysis through a unified interface that can be used toconfigure and deploy storage tests and view graphical results for those tests.

I/O Analyzer can use Iometer to generate synthetic I/O loads or a trace replay tool to deploy real applicationworkloads. It uses the VMware VI SDK to remotely collect storage performance statistics from VMwareESX/ESXi hosts. Standardizing load generation and statistics collection allows users and VMware engineers tohave a high level of confidence in the data collected. 

The virtual appliance VMware IO Analyzer is a VMware Fling. You can find it here.


  • Integrated framework for storage performance testing
  • Readily deployable virtual appliance
  • Easy configuration and launch of storage I/O tests on one or more hosts
  • Integrated performance results at both guest and host levels
  • Storage I/O trace replay as an additional workload generator
  • Ability to upload storage I/O traces for automatic extraction of vital metrics
  • Graphical visualization of workload metrics and performance results
  • Patched BASH binary to fix Shellshock vulnerability
  • Patched OpenSSL library to fix Heartbleed vulnerability
  • Added warning messages when invalid VM names are detected

I/O Analyzer Usage Modes

I/O Analyzer has a number of modes that can be used to measure a storage system’s performance: 

  • I/O Analyzer can use Iometer, an open-source synthetic I/O subsystem measurement and characterizationtool, to drive load.
  • I/O Analyzer can replay vSCSI I/O traces, either those included with I/O Analyzer or those collected and uploaded by the user, to simulate real-world I/O patterns.
  • I/O Analyzer can be used to measure storage system performance when an external load is played on thatstorage system.

I/O Analyzer also includes a number of features and utilities that allow convenient creation, scheduling, andmonitoring of tests, as well as detailed analysis of test results. 

VMware IO Analyzer Installation and Tuning can be found here.