I've been meaning to get this issue posted here for the past 4 months now. Here goes.
Back in October I tried to upgrade the RAM in my server running Zimbra FOSS but ran into some issues. I don't recall the exact version of FOSS I was running at the time but I would imagine it was current as of 10/1/08. The server is running CentOS 5.2. Went from 2GB to 10GB memory and installed kernel-PAE to allow the OS to recognize more than 4GBs of ram. All good until I tried to fire up Zimbra. It hung trying to start the MTA. After multiple tests, I removed the kernel-PAE package and Zimbra booted up just fine.
Since then, I have moved to NE and am currently running 5.0.14. I have not yet tried to install kernel-PAE for the extra RAM to show up. I'm hoping to get the opportunity to this within the next two weeks but as you can imagine, taking the mail server offline is not super fun.
Anyone else running NE on top of CentOS 5.x with more than 4GB of RAM?