Greg's quickTIP: Paging Mr. PerfMon

Establish a baseline for performance easily and you'll know just how slow is slow.

By Greg Shields

Perfmon? Haven’t we been here before? Seriously though, I’m always surprised when I talk with systems administrators who haven’t enabled any performance counters on their servers. If you aren’t aware of the historical performance of your servers, then how can you compare today’s "it's slow" with the "it's slow" from yesteryear?

Because of the changes in hardware speeds due to Moore’s law in relation to the number and scope of operating system enhancements over the years, many of our servers now sit at 3 percent utilization. So, many of us have forgotten how to effectively do performance management on our systems. If our systems are flipping between 0s and 1s for 97 percent of the time just to occupy a bored processor, there’s not much to manage.

However, the movement to systems virtualization means that we’re now just starting to begin squooshing lots of servers together to eliminate all that downtime and squeeze more useful processing out of our lazy processors. One of the key skills that is back in vogue because of this is performance monitoring and management in our systems.

If you haven’t yet enabled performance counters on your servers, consider enabling at least a few critical ones so you can keep a baseline of the performance of your servers. Some of the critical ones to keep are:

  • Disk\% Free Space
  • Disk\% Disk Time
  • Disk\Current Disk Queue Length
  • Disk\Disk Reads and Writes/Sec
  • Memory\Available Mbytes
  • Memory\Pages/sec
  • Page File\% Utilization
  • Processor\% Processor Time
  • Processor\Interrupts/sec
  • System\Processor Queue Length

Computers are deterministic creatures. What we mean by "deterministic" is that nothing inside them will change unless an external force acts upon them -- either from you, another computer or some bad software. Only if you know how your systems perform in normal situations can you identify when bad things are happening. Moreover, you don’t need complicated or expensive tools to do any of this. With Perfmon -- native to all Windows OSes, you can do this for no cost -- right out of the box.

Comment: http://mcpmag.com/columns/article.asp?editorialsid=1756#post

Greg Shields, MCSE: Security, CCEA, is a senior consultant for 3t Systems in Denver, Colo., http://www.3tsystems.com . A contributing editor to Redmond magazine and a popular speaker at TechMentor events, Greg provides engineering support and technical consulting in Microsoft, Citrix and VMware technologies. gshields@redmondmag.com