The pvmd writes error and warning messages in a log file named /tmp/pvml.uid. uid is your numeric user id (generally the number in the third colon-separated field of your passwd entry).
Try the following command to get your uid:
(grep `whoami` /etc/passwd || ypmatch `whoami` passwd) \
| awk -F: '{print $3;exit}'
If PVM was built with the SHAREDTMP option (used when a cluster of machines shares a /tmp directory), the log file will instead be named /tmp/pvml.uid.hostname.
The pvmd publishes the address of the socket to which local tasks connect in a file named /tmp/pvmd.uid. The pvmd creates the socket address file while starting up, and removes it while shutting down. Another pvmd won't start if the file already exists.
If the pvmd can't create the file because the permissions of /tmp are set incorrectly or the filesystem is full, it won't be able to start up. If the pvmd is killed with un uncatchable signal or other catastrophic event such as a (Unix) machine crash, you may need to remove the socket address file before another pvmd will start on that host.