run an asp.net application on a web farm
<p>I wanna know what is the issues and problems of running an asp.net on a web farm
I know one of them is related to managing session states and managing cached objects.
I have read about "Velocity" of microsoft that is a distributed system for managing cache and session per multi servers.
Does it solve the problem of session and cache on multi servers ?</p>

<p>Please tell me what is the other issues that I should know ?
Which of them should be considered in developing time ?</p>

<p>for example I really want to know , how resources are managed in multi servers ? 
If user upload a file (for example an image) to a server , this file is saved in a server of web farm , what happen if another server try to access to the uploaded file ?
Are the resources becomes shared in web farm ? I mean  Server.MapPath("~/uploads/image1.gif")
can always access the uploaded resource ?</p>

<p><strong>Thank you very much for your help</strong></p>
