dwmtractor: I think the version is "Zimbra Collaboration Suite 5.0" but I'm not sure if it's under "Help" and then "Version" where you find the working version info.
The installer was: /zcs-NETWORK-5.0.2_GA_1975.RHEL5_64.20080130215
So that looks like 5.0.2
reza225: I knew that I was testing on a VPS and that I'd probably end up using a dedicated machine should we decide to go ahead with the system. I haven't experienced this kind of RAM issue using Xen + CentOS VPS's before, but perhaps Java and VPS don't get along as well as they could.
If we roll with this we'll end up putting it, at the least, on a 2.4Ghz P4 w/3GB RAM + 3ware RAID 10 (SATA) over 4 drives. I think a Core 2 Duo/Quad will be a better choice though... so we can scale up to 8GB RAM if needed.
I've rebooted and currently it's sitting at ~1.9GB used... Thanks everyone for your responses... I'm going to try adding another 500MB RAM just to see how it responds, then give it a few days to see how it goes.