Re: initdb memory segment creation error

I have few other applications running on my machine but they all don't use
more than 60MB. I checked and SHMALL is in pages. I also reduced
shared_buffers and max_connections but that didn't help. Also I did ipcs
after I got the error and following is what I got -

T ID KEY MODE OWNER GROUP NATTCH SEGSZ
CPID LPID ATIME DTIME CTIME
m 131072 2 --rw------- pgsql pgsql 0
6242304 67055 67055 14:13:34 14:13:34 14:13:34
m 131073 3 --rw------- pgsql pgsql 0
5234688 67057 67057 14:14:02 14:14:02 14:14:02
m 131074 4 --rw------- pgsql pgsql 0
4235264 67059 67059 14:14:30 14:14:30 14:14:30
m 131075 5 --rw------- pgsql pgsql 0
3203072 67061 67061 14:14:57 14:14:57 14:14:57
m 131076 6 --rw------- pgsql pgsql 0
2203648 67063 67063 14:15:25 14:15:25 14:15:25
m 131077 7 --rw------- pgsql pgsql 0
1687552 67072 67072 14:15:54 14:15:54 14:15:54
m 131078 8 --rw------- pgsql pgsql 0
36478976 67074 67074 14:16:22 14:16:22 14:16:22
m 131079 9 --rw------- pgsql pgsql 0
9592832 67086 67086 14:19:10 14:19:10 14:19:10
m 131080 10 --rw------- pgsql pgsql 0
1687552 67137 67137 14:23:50 14:23:50 14:23:50
m 131119 1 --rw------- pgsql pgsql 0
11321344 67053 67053 14:13:07 14:13:07 14:13:07

Postgres did create, attach, detach shared segments but did'nt delete them.
I think these processes were forked by postmaster but why so many were
created? and why those segments not reported?

Thanks,
Fahad

On Thu, Sep 11, 2008 at 5:20 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> questions <questions(dot)612(at)gmail(dot)com> writes:
> > I am getting this error with initdb while creating shared segment -
> > "memory segment exceeded available memory or swap space. To reduce the
> > request size (currently 1785856 bytes), reduce PostgreSQL's
> shared_buffers
> > parameter (currently 50)) and/or its max_connections parameter (currently
> > 13)."
> > Total memory is 256 MB and memory available to user processes is 178 MB.
> > It's not an issue with shared segment exceeding SHMMAX but value of
> SHMMAX
> > is 67108864 and SHMALL is 8192. It is not exactly a Postgresql problem
> but
> > what am I missing here?
>
> Hm, what else is running on the box? PG itself should fit in 256MB but
> if you've got other stuff hogging memory, you might have little choice
> but to buy more RAM.
>
> (You should also double-check what SHMALL is measured in on your
> platform; maybe that 8192 isn't pages but bytes ...)
>
> regards, tom lane
>