Re: PG 7.0.3 & RH 7 IPC problems?

DHSC Webmaster <webmaster(at)dhs-club(dot)com> writes:
> [postgres(at)atl01371 data]$ nohup postmaster -D /usr/local/pgsql/data -i
> -B 128 -N 64 > /usr/local/pgsql/data/logs/log.txt
> IpcMemoryCreate: shmget failed (Invalid argument) key=5432001,
> size=2048000, permission=600

Not sure about Linux, but on HPUX there are two possible reasons for
shmget to return EINVAL:

[EINVAL] size is less than the system-imposed minimum or
greater than the system-imposed maximum.

[EINVAL] A shared memory identifier exists for key but the
size of the segment associated with it is less
than size and size is not equal to zero.

In other words, you could get this if there is an old segment of smaller
size and the same key still laying about, which there might well be if
you were foolish enough to kill -9 the old postmaster. Use ipcs and
ipcrm to check and clean up.

7.1 uses a slightly different approach that hopefully avoids this
particular failure scenario...

regards, tom lane