PRB: ADO.NET ConnectionPoolManager throws OutOfMemoryException when trying to update it's Perf Counters

When running into this problem, I have had some success working-around it by increasing the value on the fileMappingSize attribute on the performanceCounters element within the config file.

   \\configuration\system.diagnosticts\performanceCounters[@fileMappingSize]

In most cases, you will need to modify this either in the machine.config or the root web.config (c:\inetpub\wwwroot\web.config), otherwise it may not apply properly.

See the MSDN docs for details and use at your own risk:

http://msdn.microsoft.com/en-us/library/ms229387