系统技术非业余研究

官网：http://freshmeat.net/projects/fio/

fio is an I/O tool meant to be used both for benchmark and stress/hardware verification. It has support for 13 different types of I/O engines (sync, mmap, libaio, posixaio, SG v3, splice, null, network, syslet, guasi, solarisaio, 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, NetBSD, OS X, and OpenSolaris.

Ubuntu下可以用apt-get install fio安装就好。

这个工具最大的特点是使用简单，支持的文件操作非常多, 可以覆盖到我们能见到的文件使用方式:
sync：Basic read(2) or write(2) I/O. fseek(2) is used to position the I/O location.
psync：Basic pread(2) or pwrite(2) I/O.
vsync: Basic readv(2) or writev(2) I/O. Will emulate queuing by coalescing adjacents IOs into a single submission.
libaio: Linux native asynchronous I/O.
posixaio: glibc POSIX asynchronous I/O using aio_read(3) and aio_write(3).
mmap: File is memory mapped with mmap(2) and data copied using memcpy(3).
splice： splice(2) is used to transfer the data and vmsplice(2) to transfer data from user-space to the kernel.
syslet-rw： Use the syslet system calls to make regular read/write asynchronous.
sg：SCSI generic sg v3 I/O.
net ： Transfer over the network. filename must be set appropriately to `host/port’ regardless of data direction. If receiving,
only the port argument is used.
netsplice： Like net, but uses splice(2) and vmsplice(2) to map data and send/receive.
guasi The GUASI I/O engine is the Generic Userspace Asynchronous Syscall Interface approach to asycnronous I/O.

还可以控制io depth对于测试磁盘的性能很有帮助，对结果的解读也做的很明白。

典型的使用如下：
fio –filename=/dev/sdc1 –direct=1 –rw=randread –bs=4k –size=60G –numjobs=64 –runtime=10 –group_reporting –name=fileXXX

玩的开心。