NFS and Server resources.

[Martin Jessa]

Hi guys.

I need some hints to figure out how much RAM and how fast CPU(s) would be required to serve NFS mounted file system on a RAID 5 array for 2 servers running:
1. mail(pop3/imap) and MySQL with user data. 
2. web server (apache+mod_php,mod_perl) and radius server
 for about 3000 users?
The users will also be able to ftp to the file server and upload/download their files.
The link speed is 100mbit.

Thanks,
YazzY