Re: hot restart of posgtresql

Tom Lane wrote:
> ngaleyev(at)wavelengthmail(dot)com writes:
> > 2007-07-03 19:20:42 EDT 2928 FATAL: could not create shared memory
> > segment: Invalid argument
> > 2007-07-03 19:20:42 EDT 2928 DETAIL: Failed system call was
> > shmget(key=5432001, size=3276259328, 03600).
> > 2007-07-03 19:20:42 EDT 2928 HINT: This error usually means that
> > PostgreSQL's request for a shared memory segment exceeded your kernel's
> > SHMMAX parameter. You can either reduce the request size or reconfigure
> > the kernel with larger SHMMAX. To reduce the request size (currently
> > 3276259328 bytes), reduce PostgreSQL's shared_buffers parameter (currently
> > 393216) and/or its max_connections parameter (currently 250).
>
> > heres my sysctl:
> > kernel.shmmax=4294967296
> > kernel.shmall=536870912
>
> Why have you got SHMALL set to half a GB when you have Postgres
> configured to ask for over 3 GB?

Hmm, isn't shmall measured in pages?

I think the problem may be that he changed the settings in sysctl.conf
but he hasn't rebooted since, so the kernel is running with other
settings. Trying with sysctl -w to change the actual values might prove
helpful.

--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.