When I install it not a root I have the same situation: nohup.out is empty and this is a zdesktop.out.
Code:
0 INFO [main] log - Logging to org.slf4j.impl.Log4jLoggerAdapter(org.mortbay.log) via org.mortbay.log.Slf4jLog
477 INFO [main] log - jetty-6.1.5
813 INFO [main] log - No Transaction manager found - if your webapp requires one, please configure one.
Zimbra server process is running as uid=500 euid=500 gid=500 egid=500