1. indicator-multiload:
可视化图形显示
sudo apt-get install indicator-multiload
2. indicator-sysmonitor:
以百分比形式显示资源占用情况
https://launchpad.net/indicator-sysmonitor
3. indicator-netspeed:
数值显示网速
http://ppa.launchpad.net/nilarimogard/webupd8/ubuntu/pool/main/i/indicator-netspeed/
log out and log back in after installed
原文：http://www.cnblogs.com/turtle920/p/5745995.html