"Ed L." <pgsql@bluepolka.net> writes:
> A power failure led to failed postmaster restart using 7.4.6 (see output
> below). The short-term fix is usually to delete the pid file and restart.
> I often wonder why ipcs never seems to show the shared memory
> block in question?
The shared memory block would certainly not still exist after a system
reboot, so what we have here is a misleading error message. Looking at
the code, the most plausible explanation appears to be that
shmctl(IPC_STAT) is failing (which it ought to) and returning some errno
code different from EINVAL (which is the case we are expecting to see).
What platform are you on, and what does its shmctl(2) man page document
as error conditions?
regards, tom lane