If you don't and you simply want to add an extra front-end server and for example on the first front-end server you put the virtual directories folder on the F drive. And the second web server does not have a F-drive you are confronted with all sorts of errors on the 2nd server when you open up a site:
Event Type: Error Event Source: Windows SharePoint Services 3 Event Category: Runtime Event ID: 6610 Date: 1-11-2007 Time: 9:44:34 User: N/A Computer: 2ndFrontEndServer Description: Safe mode did not start successfully. This page has encountered a critical error. Contact your system administrator if this problem persists. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
And this error for each webpart that is on a page : "Web Part Error: This page has encountered a critical error".
Kinda freaky eh? :) I checked IIS to check whether all the necessary dll's were copied in the bin folder and checked the web.config to see if everything matched the first front-end server and.. it did! So what is causing this behavior? Next I tried adding a third server to determine that the 2nd server wasn't causing this problem and luckily enough the 3rd server was displaying the same behavior. Then I tried to deploy a solution across the farm and while deploying an the following error was raised:
2ndFrontEndServer: http://portal/ : Portal 2007 : Error: The creation of this directory failed: f:\Inetpub\wwwroot\wss\VirtualDirectories\portal80\bin. Could not find a part of the path 'f:\Inetpub\wwwroot\wss\VirtualDirectories\portal80\bin'. 2ndFrontEndServer : Could not find a part of the path 'f:\Inetpub\wwwroot\wss\VirtualDirectories\portal80\bin'.
Very logical error since there is no F drive on the 2nd web server. And seeing this error made me realize that everything must be identical on both servers, so when I changed the driveletter on the 2nd webserver from E to F, everything worked like a charm. No more errors on the pages, no more errors in the eventviewer and no more errors when deploying a solution!