ASP.NET 2.0 Features: app_offline.htm

There is a simple way to bring down your ASP.NET 2.0 application. The only thing you have to do is to create simple html file called App_offline.htm and deploy it to your ASP.NET 2.0 web application root directory. The rest is handled by ASP.NET runtime internal routines.

The way app_offline.htm works is that you put the file in the root directory of the application. When ASP.NET sees it, it will shut-down the app-domain for the application (and not restart it for requests) and instead send back the contents of the App_offline.htm file in response to all new dynamic requests for the application. When you are done updating the site, just delete the file and it will come back online.