故障log：
%C4K_IOSMODPORTMAN-4-POWERSUPPLYBAD: Power supply 2 has failed or been turned off
在单机的情况下，我们可以很容易的判断是哪一个Power Supply故障了，但是在VSS环境下，没有注意过这类log，可能有点迷糊，这哦Power supply 2是指Switch 1的PS呢还是Switch 2呢？
实际情况如下：
如果是Standby的电源故障了，会是如下情况：
*May 1 09:23:45.234: %C4K_IOSMODPORTMAN-4-POWERSUPPLYBAD: STANDBY:Power supply 2 has failed or been turned off
*May 1 09:23:50.252: %C4K_IOSMODPORTMAN-6-POWERSUPPLYGOOD: STANDBY:Power supply 2 is okay
如果是Active的电源故障了，会是如下情况：
*Dec 09 18:57:08.526: %C4K_IOSMODPORTMAN-4-POWERSUPPLYBAD: Power supply 2 has failed or been turned off
*Dec 09 18:57:13.527: %C4K_IOSMODPORTMAN-6-POWERSUPPLYGOOD: Power supply 2 is okay
另外，我们也可以通过show power detail命令去判断：
Power fail interrupts received on slot 1: 0
Power fail interrupts received on slot 2:
.......
以及Watts Used of System Power
Watts used of Chassis Inline Power
查看PS故障的信息，可以通过如下命令：
show clock
show ver
show env
show power detail
show log