OESll sp1 on VMware ESXi 5.1, plenty of RAM and processing power

We've had our new OES11 sp1 server up for about 3 weeks. We got an error stating /var was getting full, so I deleted a bunch of migration project files. Now the error has returned. "/var/opt/novell/imanager/nps" is the major offender; however, I'm not sure what to clean nor a "safe" way to do it. "/var" is it's own 4GB volume. I get this error when there's about 100MB left. What to do?