SQLIOSim
SQLIOSim is a great utility to perform tests on disk subsystems. These tests simulate read, write, checkpoint, backup, sort, and read-ahead activities for Microsoft SQL Server.
The SQLIOSim utility has been upgraded from the SQLIOStress utility and more accurately simulates the I/O patterns of Microsoft SQL Server 2005, of SQL Server 2000, and of SQL Server 7.0.
SQLIOSim can run on a server without even requiring an installation of SQL Server, to allow to test new hardware before SQL Server is installed.
The general misunderstanding is that SQLIOSim is a performance measurement tool.
This is not correct. SQLIOSim is a correctness and stress tool, and you should use it when you want to check if your IO subsystem is functioning correctly.
To give it a try:
Download and run the tool, open the sqliosim.log.xml output file and look for RED errors.
The YELLOW errors (despite the name "errors") are just warnings, and usually are related to Outstanding I/Os. Unless the # of outstanding IO request is excessive, these are not the kind of errors that you are looking for.
In fact that the workload caused by SQLIOSim is very heavy. If you want to check the system under a more realistic scenario, consider changing the parameters in the config file "sqliosim.cfg.ini" (MaxOutstandingIO, TargetIODuration should help yourself in getting closer to it).
Other useful articles not to miss:
How to use the SQLIOSim utility to simulate SQL Server activity on a disk subsystem
https://support.microsoft.com/kb/231619
SQLIOSim - Outstanding I/O Warnings
https://blogs.msdn.com/psssql/archive/2007/04/10/sqliosim-outstanding-i-o-warnings.aspx
SQLIOSim available for download
What happened to SQLIOStress?
https://blogs.msdn.com/psssql/archive/2006/11/27/what-happened-to-sqliostress.aspx
SQL Server 2000 I/O Basics
https://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/sqlIObasics.mspx
- Beatrice Nicolini -