I ran the sysdumpstart -p, which worked a treat.
However, I have a follow on question.
As this crashed the server and caused it to reboot, would any of you know whether it would cause on reboot /etc/environment not to be read ?
I ask as out Informix databases did not start when running smitty clstart, and the DB experts reckon it was due to EXTSHM=ON not being set from /etc/environment
ta