I/O Stress Test Tools

Large numbers of performance problems are related to mis-configured and under performing I/O or storage area network (SAN) subsystems. It is strongly recommended to test the SAN from a performance perspective. The following tools are recommended for stress testing a SAN.


SQLIO is a tool provided by Microsoft which can be used to determine the I/O capacity of a given configuration. For configuration and usage instructions, and to download the tool, see the following Web site at http://www.microsoft.com/downloads/details.aspx?FamilyID=9a8b005b-84e4-4f24-8d65-cb53442d9e19&DisplayLang=en.

SQLIO Stress

The SQLIOStress utility simulates the read and writes patterns of a heavily loaded server that is running SQL Server, and it uses a Write Ahead Logging (WAL) protocol that is similar to the protocol that SQL Server uses.

These patterns include heavy page insert/split simulations, inserts, updates, checkpoint stress scenarios, read aheads, sorts, hashes, and backup scan activities that include large and varied scatter and gather I/O requests. The simulation also imposes heavy data file activity that requires high transaction log activity.

For configuration and usage instructions and to download the tool, see “How to use the SQLIOStress utility to stress a disk subsystem such as SQL Server” at the following Web site: http://support.microsoft.com/default.aspx?scid=kb;en-us;231619.