When started, pvmd3 creates a couple of files keeping its state:
pvm[dl].<UID> . By default, it puts them into /tmp.

The problem is, PVM daemon doesn't touch those files after that. Thus, in
case there is no PVM activity for 10 days or such, the state files will get
removed by tmpwatch. This renders PVM majorly messed up, when only
kill(1)ing a daemon and restarting it can help.

The proper solution is:

a. In %postinstall script:

mkdir -p /var/run/pvm
chmod 1777 /var/run/pvm


b. In /etc/init.d/pvm:

export PVM_TMP=/var/run/pvm