A week or so ago, my users of Outlook Web Access (OWA) began to be unexpectedly logged off. Being typical users, they did not report it for about a week, and I know of know changes to the system, configuration. When they are logged off, a message is posted in the system event log that: A worker process with process id of '....' serving application pool 'MSExchangeOWAAppPool has requested a recycle because it reached its virtual memory limit. I tried disabling the virtual memory limit, and it returned on IIS restart. I raised the limit and restarted IIS, and the problem continues.
My environment is Windows Server 2003 R2, 64-bit, with Exchange 2007, 64-bit, installed. The machine has 18GB of memory installed, with a 16GB page file size. The machine runs IIS 6.0. The memory usage peak is around 16GB. I am using OWA in IE 8.0 and set to a private computer. (I have tried it in Firefox and as a public computer, with similar issues). I could find nothing of this in Microsoft's knowledge base.
Does anyone have any suggestions?