iotop命令是专门显示硬盘IO的命令，界面风格类似top命令。这个命令只有在kernelv2.6.20及以后的版本中才有。
1、直接yum安装，rh6的光盘里有包。
yum install iotop
2、命令参数介绍
-o, --only
Only show processes or threads actually doing I/O, instead of showing all processes or threads. This can be dynamically toggled by pressing o.
-b, --batch
Turn on non-interactive mode. Useful for logging I/O usage over time.
-n NUM, --iter=NUM
Set the number of iterations before quitting (never quit by default). This is most useful in non-interactive mode.
-d SEC, --delay=SEC
Set the delay between iterations in seconds (1 second by default). Accepts non-integer values such as 1.1 seconds.
-p PID, --pid=PID
A list of processes/threads to monitor (all by default).
-u USER, --user=USER
A list of users to monitor (all by default)
-P, --processes
Only show processes. Normally iotop shows all threads.
-a, --accumulated
Show accumulated I/O instead of bandwidth. In this mode, iotop shows the amount of I/O processes have done since iotop started.
-k, --kilobytes
Use kilobytes instead of a human friendly unit. This mode is useful when scripting the batch mode of iotop. Instead of choosing the most appropriate unit iotop will dis‐
play all sizes in kilobytes.
-t, --time
Add a timestamp on each line (implies --batch). Each line will be prefixed by the current time.
-q, --quiet
suppress some lines of header (implies --batch). This option can be specified up to three times to remove header lines.
-q column names are only printed on the first iteration,
-qq column names are never printed,
-qqq the I/O summary is never printed.
3、使用截图
[root@localhost tmp]# iotop -o
iotop命令的键盘快捷键：
1、左右箭头改变排序方式，默认是按IO排序
2、r键是反向排序
3、o键是只显示有IO输出的进程
4、同样q是退出
