Contributed by Doug Hughes

The following is a list of tools that one can use for benchmarking or measuring the performance of a filesystem/volume. It is by no means complete and any additions are greatly appreciated.

1. iostat: builtin
2. sar: like iostat, builtin
3. vxstat: like iostat, comes with VxVM, provides breakouts on things like read-modify writes, reconstruct writes, etc, and and can work on volume, plex, or subdisk level
4. lmbench: Written by Larry McVoy while at SGI, presented at a Usenix conference in 1996, and now offered by bitmover.com
5. IT Service Vision (formerly SAS/CPE) is a tool for performance measurement.
6. iozone is originally from comp.sources.misc days (1994!), but with an improved look and usability. It's got lots of new features for benchmarking filesystems and simulating loads.
7. Vxbench is available free from Veritas and is a good tool for benchmarking Veritas volumes and filesystems (and even non-veritas volumes and filesystems). Capabilities examples here
8. Proctool is a free, unsupported process tool from Sun that is capable of displaying per-process I/O results (manual configuration). caveat: if you are in a foreign country, you must set LC_ALL=C for it to work.
9. Soliddata hasa product for optimizing Oracle hot-spots. I know of no first hand experiences positive or negative with this product.