Question

Are there any performance penalties running .NET 4.0 app from shared network folder? I found what app starts slower but didn’t noticed any slow down while using it, but not sure about it.

Answer 1

When running an executable over the network, Windows does not bring the entire application over the network at application startup. This is done to speed startup times (and there’s no point is downloading that 700MB embedded AVI resource if you never actually use it).

This means that periodically, as new pages from the executable image are required, Windows will go back to the network to retrieve them.

The method in which this is accomplished is that if your application happens to hit a page of memory that is not present, a standard page fault will trigger, telling Windows it needs to fill that page. If the network happens to be down at that moment, Windows will be unable to satisfy the page-fault. There’s no way to recover from this, so Windows throws an EXCEPTION_IN_PAGE_ERROR (0xC0000005).

There are three ways to handle this:

• do nothing and let the application die. Tell the customer to fix their network
• trap the error, explaining that the application must be terminated now, and telling the user that their network is to blame
• set the IMAGE_FILE_NET_RUN_FROM_SWAP PE image option. This will instruct Windows to copy the entire executable over the network at application load time. This will increase network traffic and user wait times (at application launch time), but avoid the error