Exchange 2003/2007 Windows 2003 SP2. High Non Paged Pool memory

Something we see a few of is memory and Paged and Non-Paged pool bytes running very high and causing system instability. This often rears its head in the form of events in the event logs, MOM reporting this, or in worse case scenareos Exchange grinding to a halt or failing altogether.

This can happen in a situation when NPP (Non Paged Pool memory) usage gets too high, what is high depends on several factors such as the amount of physical memory and how this is tuned (3GB switch and USERVA). The document https://technet.microsoft.com/en-us/library/aa997270(EXCHG.65).aspx gives good steps on how we can monitor this (using Perfmon) and "what is high".

A good place to start if NPP is running high if Windows 2003 SP2 is in the mix is TCPchimney usage, this has been seen to cause some issues here. https://support.microsoft.com//kb/948496 But before doing this log a call with support to help troubleshoot! Something like a pool snap (takes a snapshot of memory usage per tag over a period of time) gives a good idea what is consuming all the NPP memory.

Another area to look into is SystemPages and how these are set, (https://support.microsoft.com/kb/815372) the excellent ExBPA will pick up on this and it can have a great effect on performance.

Another area that catches a lot of people out is the graphics driver that is used on the server, anything "fancy" can and will adjust some of the performance settings (like system pages). So its always advisable to revert back to a standard Windows VGA driver. Its an Exchange server not a gaming machine :)

Comments

• Anonymous
  August 12, 2008
  Is your cluster failing over? Is it the HTTP resource going first? This seems the first resource to fail