The utility vovcleanup is used to clean old log files from /tmp and from the server working directory.

vovcleanup: Usage Message
      vovcleanup  -- Cleanup log files in host and project directory
                     Rules can be customized in server working
                     An example of cleanup.config.tcl can be found here:
      -v         -- Increase verbosity
      -h         -- This message
      -n         -- Show files to delete, but do not delete them
      -proj      -- Cleanup project log files
      -host      -- Cleanup log files in /tmp,/usr/tmp,/var/tmp
      % vovcleanup -host
      % vovcleanup -n -proj
      % vovcleanup -proj
      vovcleandir      -- to cleanup old log files in a directory.
      nc clean         -- to cleanup old files generated by NetworkComputer.
To cleanup old log files in the /tmp and /usr/tmp directory, use:
% vovcleanup -host 
To cleanup log files and cache files in the project configuration directory, use:
% vovcleanup -proj
If you want to first see which files are going to be cleaned up, use the -n option as in:
% vovcleanup -proj -n

Cleaning rules can be modified in cleanup.config.tcl located in the Server Working Directory.