Perfstat is a diagnostic data collection tool for NetApp filers. If and when they experience performance issues, NetApp Support will likely ask for perfstat to be run against the ailing filers. This is (hopefully) not something that is done often, and therefore, the details of how to run it may get rusty, which is problematic in the middle of an availability storm.
We wrote xnperfstat in late 2008 to provide a cleaner and more straightforward method to run perfstat: it performs perfstat housekeeping chores for us, with options geared directly towards situations where support cases are open. It can also be run on a “continuous” basis from cron (for cases where the data collection has to be done over a period of days), storing and rotating output files.
See the README for details.