Checks for overtemperature, fans, psu, and nfs operations/second on Network
Appliance Filers.

Returns:
* OK if temp, fans, psu OK and Ops/Sec below warning and critical Thresholds
(default is warning=3500, critical=5000)
** Note: See the specifications for your Filer model for the thresholds !
* Returns Warning if NFS Ops/Sec is above warning threshold (default 3500, or
specified by -o command line option)
* Returns Critical if NFS Ops/Sec is above critical threshold ( -m option, or
default 5000), or if overtem, psufault, or fanfault detected.