We found that server are hang-up now,
e.g. can't telnet, can't access app service (but can ping it). 
what do then it?

kSar Info:
OS Type: Linux (automatically detected)
Kernel Release: 2.6.18-128.el5
Hostname: ydcvmapp02
Start of SAR: 11/19/10
End of SAR: 11/19/10
Time range information:
First data point: Fri Nov 19 00:00:01 CST 2010
Last data point: Fri Nov 19 13:44:01 CST 2010
Graph range:
First data point: Fri Nov 19 00:00:01 CST 2010
Last data point: Fri Nov 19 13:44:01 CST 2010
Detected bottlenecks:
 CPU 1 wio over 25.0
 CPU 0 usr over 25.0
 CPU 1 usr over 25.0
 CPU 0 wio over 25.0
 CPU all wio over 25.0
 CPU 0 system over 50.0
 CPU 1 system over 50.0
 CPU all usr over 25.0
 CPU all system over 50.0
Causation:
The issue happen suddenly,and keep a few minutes, then disappear, after check memory use up caused this.

当memory用尽，os都做了些什么？而用完CPU?

http://testwo.com/attachment/201011/22/7639_1290392361WH67.jpg
http://testwo.com/attachment/201011/22/7639_1290392428q5pc.jpg