My situation now: The file server is a Poweredge 2950 with dual Xeon Woodcrest 5140s, 2 GB of RAM, and four 146 GB 10k SAS drives in one big RAID 5 volume on a PERC5i. The amount of RAM seems ...
1-2 GB is for low end servers. If you add MS SQL or other database engines, 2-4 GB.