Hmm, nice little error when trying to start db2 on solaris 10, stating that it was unable to start up the database and i should check my SHM settings!

Arrgh!

prctl reported correct project settings, so tried truss:-

# truss -f db2start
truss: cannot trace set-id or unreadable object file: db2start

Cue alarm bells, proven by trusty "ls":

# truss -f db2start
-rwsr-xr-x 1 root root 238584 Jul 10 12:28 db2start

Add root to the user.db2inst1 project with a quick projmod -a -U root user.db2inst1 and try again.