Eric Smith <eric_h_smith(at)mac(dot)com> writes:
> Log file says "could not create shared memory segment". It also says
> that I should change max_connections or shared_buffers.
> Error message claims that max_connections is 23, but postgresql.conf
> has this listed as 20.
The autovacuum workers get added on.
> Error message claims that shared_buffers is 300, but postgresql.conf
> has this listed as 2400kB.
Same thing, different units.
Anyway, you left out the interesting part of the error message,
ie the kernel error code. If it's "Cannot allocate memory" then
you probably need to increase SHMALL.
regards, tom lane