I run Zimbra 5.0.5 on Ubuntu 6.06 LTS Server since 3 weeks with 6 e-mail addresses in 2 domains.
I did a first analysis of how zimbra is running in my live environment and I noticed that I have a lot of file pairs /tmp/zmcontrol.error.* and /tmp/zmcontrol.status.* with a file size of 0 or 20 - 40 bytes long. BTW: The server never was stopped / started or restarted manually.
Checking the /var/log/zimbra.log* files does not show anything in common. As I receive a lot of spam (which luckily gets filtered out by Zimbra), there is activity on the incoming port and also at the same minute while the status and error file pair was created (according to the time stamp of the file).
This is not a disk space issue but there is some clean up missing and makes it more complicated to keep track on the files in /tmp - any hints?