Welcome to Part Four of our Server Hang troubleshooting series. Today we are going to discuss PTE depletion and Low Physical Memory conditions and how those two issues can lead to server hangs. In our post on the /3GB switch we mentioned that in general, a system should always have around 10,000 free System PTE’s. Although we normally see PTE depletion issues on systems using the /3GB switch, that does not necessarily mean that using the /3GB switch is going to cause issues – what we said was that the /3GB switch is intended to be used in very specific instances. Tuning the memory further by using the USERVA switch in conjunction with the /3GB switch can often stave off PTE depletion issues. The problem with PTE depletion is that there are no entries logged in the Event Viewer that indicate that there is a resource issue. This is where using Performance Monitor to determine whether a system is experiencing PTE depletion comes into play. However, Performance Monitor may not identify why PTE’s are being depleted. In instances where a process has a continually rising handle count that mirrors the rate of PTE depletion, it is fairly straightforward to identify the culprit. However, more often than not we have to turn to a complete dump file to analyze the problem.