Re: postgresql 8.4 semaphores ...

[christos%astron.com@localhost (Christos Zoulas)]

In article <20100606133900.GB27464%fastmail.fm@localhost>,
Malcolm Herbert  <mjch%mjch.net@localhost> wrote:
>On Sun, Jun 06, 2010 at 12:37:15PM +0200, Jean-Yves Migeon wrote:
>|On 06/06/10 10:39, Malcolm Herbert wrote:
>|>still, postgresql fails to start with an error complaining about
>semaphores again (instead of memory):
>|>
>|>|FATAL:  could not create semaphores: No space left on device
>|>|DETAIL:  Failed system call was semget(31, 17, 03600).
>|>|HINT:  This error does *not* mean that you have run out of disk space.
>|>|       It occurs when either the system limit for the maximum number
>of semaphore sets (SEMMNI), or the system wide maximum number of
>semaphores (SEMMNS), would be exceeded.  You need to raise the
>respective kernel parameter.  Alternatively, reduce PostgreSQL's
>consumption of semaphores by reducing its max_connections parameter
>(currently 13).
>|>
>|>starting to tear out my hair here ...
>|
>|Hmm, I don't think that the max number of sets or identifiers is the
>|problem here, but rather the maximum number of memory that could be
>|shared for locking. Do you still have ENOSPC when you increase
>|'kern.ipc.shmmaxpgs'?
>
>bumped that to 16384 (up from 4096) and still get the same error ...
>what would be a suitable upper bound for this value?

Can you ktrace -i the process and see which system calll fails?

christos