fio is an I/O tool meant to be used both for benchmark and stress/hardware verification. It has support for 12 different types of I/O engines (sync, mmap, libaio, posixaio, SG v3, splice, null, network, syslet, guasi, and more), I/O priorities (for newer Linux kernels), rate I/O, forked or threaded jobs, and much more. It can work on block devices as well as files. fio accepts job descriptions in a simple-to-understand text format. Several example job files are included. fio displays all sorts of I/O performance information. It supports Linux, FreeBSD, and OpenSolaris.
License: GNU General Public License (GPL)
Changes:
Proper file sharing between jobs was added,
complete with various lock types and counts. Lots
of bugs were fixed, including critical ones. Users
should upgrade.