IOzone is a filesystem benchmark tool. The benchmark generates and measures a variety of file operations. Iozone has been ported to many machines and runs under many operating systems. Iozone is useful for performing a broad filesystem analysis of a vendor’s computer platform.

While computers are typically purchased with an application in mind it is also likely that over time the application mix will change. Many vendors have enhanced their operating systems to perform well for some frequently used applications. Although this accelerates the I/O for those few applications it is also likely that the system may not perform well for other applications that were not targeted by the operating system.

An example of this type of enhancement is: Database. Many operating systems vendors have tested and tuned the filesystem so it works well with databases. While the database users are happy, the other users may not be so happy as the entire system may be giving all of the system resources to the database users at the expense of all other users. As time rolls on the system administrator may decide that a few more office automation tasks could be shifted to this machine.

The load may now shift from a random reader application (database) to a sequential reader. The users may discover that the machine is very slow when running this new application and become dissatisfied with the decision to purchase this platform. By using Iozone to get a broad filesystem performance coverage the buyer is much more likely to see any hot or cold spots and pick a platform and operating system that is more well balanced.

Benchmark Features:

ANSII C source
POSIX async I/O
Mmap() file I/O
Normal file I/O
Single stream measurement
Multiple stream measurement
Distributed fileserver measurements (Cluster)
POSIX pthreads
Multi-process measurement
Excel importable output for graph generation
Latency plots
64bit compatible source
Large file compatible
Stonewalling in throughput tests to eliminate straggler effects
Processor cache size configurable
Selectable measurements with fsync, O_SYNC
Builds for: AIX, BSDI, HP-UX, IRIX, FreeBSD, Linux, OpenBSD, NetBSD, OSFV3, OSFV4, OSFV5, SCO OpenServer, Solaris, MAC OS X, Windows (95/98/Me/NT/2K/XP)