Thread: Shared memory segment error

Shared memory segment error

From
Alexander Cohen
Date:
Hi, sometimes ill get this error:

FATAL:  could not create shared memory segment: Cannot allocate memory
DETAIL:  Failed system call was shmget(key=2, size=4153344, 03600).
HINT:  This error usually means that PostgreSQL's request for a shared
memory segment exceeded available memory or  swap space. To reduce the
request size (currently 4153344 bytes), reduce PostgreSQL's
shared_buffers parameter (currently 400) and/or its max_connections
parameter (currently 20).
    The PostgreSQL documentation contains more information about shared
memory configuration.

I was what exactly this shared memory space is used for and what size
is good to set it to. I need to be able to start up many backends
(postgres) without using the postmaster.

thanks!

--
Alexander Cohen
http://www.toomuchspace.com
(819) 348-9237
(819) 432-3443


Re: Shared memory segment error

From
"Joshua D. Drake"
Date:
Hello,

Which OS are you running? If you are running Linux (RH or SuSE) you can
just increase the setting per the sysctl.conf

kernel.shmmax = 65536 (64 megs or whatever you wish).

Sincerely,

Joshua D. Drake


Alexander Cohen wrote:

> Hi, sometimes ill get this error:
>
> FATAL:  could not create shared memory segment: Cannot allocate memory
> DETAIL:  Failed system call was shmget(key=2, size=4153344, 03600).
> HINT:  This error usually means that PostgreSQL's request for a shared
> memory segment exceeded available memory or  swap space. To reduce the
> request size (currently 4153344 bytes), reduce PostgreSQL's
> shared_buffers parameter (currently 400) and/or its max_connections
> parameter (currently 20).
>     The PostgreSQL documentation contains more information about
> shared memory configuration.
>
> I was what exactly this shared memory space is used for and what size
> is good to set it to. I need to be able to start up many backends
> (postgres) without using the postmaster.
>
> thanks!
>


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