OWA stops working and users get ‘page could not be displayed’ errors
If your users suddenly begin complaining of ‘page could not be displayed’ errors when accessing OWA (or any web page hosted with IIS, for that matter) - it could be that they’re victims of your IIS server refusing connections due to low available nonpaged pool memory. Follow the directions in this article, to identify what driver(s) may be leaking memory and leading to this situation.
You also have the option to decrease the threshold on when IIS will stop accepting connections (KB934878), but I’d recommend against that, if at all possible. Try to identify what is leading to the situation first.
To see if you have less than 20MB of nonpaged memory available, open Task Manager and go to the Performance Tab and in the Kernel Memory area, note the value for nonpaged memory. Take this number and subtract it from 128MB (if you’re running with the /3GB switch) - and you’ll get how much is left. In my case we had a server with 128MB - 120MB = 8MB left, and we were getting the Connections_Refused errors logged in the HTTPERR.log files as described by David Wang’s post.
Here are some steps on how to identify which drivers are identified with the poolmon tags: KB298102. Use the findstr method, I didn’t have luck when searching using windows explorer.
