Re: [HACKERS] postmaster failure with 2-23 snapshot

> vlad: postmaster -i
> IpcMemoryCreate: shmget failed (Invalid argument) key=5432001,
> size=1137426, permission=600

I think shmget returns that error code when the requested size is
larger than the system limit on shared memory block size.  Check
your kernel parameters (SHMMAX and friends).

You might find that starting the postmaster with a smaller value
of -N is an easier answer than reconfiguring your kernel.
        regards, tom lane