[root@NB ok]# echo chenlin|base64;echo

Y2hlbmxpbgo=

[root@NB ok]# yum search iotop

Loaded plugins: fastestmirror, refresh-packagekit, security

Loading mirror speeds from cached hostfile

 * base: mirrors.btte.net

 * extras: mirrors.btte.net

 * updates: mirrors.tuna.tsinghua.edu.cn

============================== N/S Matched: iotop ==============================

iotop.noarch : Top like utility for I/O

  Name and summary matches only, use "search all" for everything.

[root@NB ok]# yum install iotop