I said:
> The fork-failed messages suggest very strongly that you are running out
> of kernel resources when you get more than a dozen or so server
> processes going. Perhaps you are too low on swap space, or need to
> enlarge the kernel's file table size.
It's also possible that you are hitting a kernel limit on number of
processes for a single user ID. See the TIP near the bottom of
http://www.ca.postgresql.org/users-lounge/docs/7.2/postgres/regress-run.html
regards, tom lane