Postgres startup

After using the following:

nohup postmaster -i -D /var/lib/pgsql/data >logfile 2>&1 </dev/null &


I get this in the logfile:

DEBUG:  database system shutdown was interrupted at 2005-04-11 16:09:06 SAST
DEBUG:  ReadRecord: invalid resource manager id 155 at 0/766DB9C
DEBUG:  invalid primary checkpoint record
DEBUG:  ReadRecord: invalid resource manager id 159 at 0/766DB5C
DEBUG:  invalid secondary checkpoint record
FATAL 2:  unable to locate a valid checkpoint record
DEBUG:  startup process (pid 13807) exited with exit code 2
DEBUG:  aborting startup due to startup process failure
[1]+  Exit 1                  nohup postmaster -i -D /var/lib/pgsql/data
 >logfile 2>&1 </dev/null

Is there any way to get the db running?

Thanks
Andy