Thought I would give my two cents on this. We use the following specifications for 175 Zimbra users...
VMware ESX 4.0 Update 1
CentOS 5.4 64-bit
8 gigabytes of memory
2 vCPUs
We have about 75 users using the AJAX interface and the rest are POP. We have been using Zimbra for over a year, and so far no problems related to ESX, virtual hardware, or 64-bit operating systems. In general, I feel its best to use 64-bit operating systems and applications whenever possible, especially in the server environment. The desktop environment is a completely different ball game. |