Re: shared_buffers Question

I've been running a postgres server on a Mac (10.3, 512MB RAM) with 200
clients connecting for about 2 months without a crash. However just
yesterday the database and all the clients hung. When I looked at the
Mac I'm using as the postgres server it had a window up that said that
there was no more disk space available to write memory too. I ended up
having to restart the whole machine. I would like to configure postgres
so that is does not rely so heavily on disk-based memory but, rather,
tries to stay within the scope of the 512MB of physical memory in the
Mac.

Am I correct in thinking that lowering that value of shared_buffers in
postgresql.conf will reduce the amount of disk space that is swapped
for memory?

I lowered the value from 2000 down to 500. Was that the right thing to
do or should I have gone the other way? Any other settings I should
look at? Thanks!

On Sat, 2004-07-31 at 10:25, Joe Lester wrote:
> I've been running a postgres server on a Mac (10.3, 512MB RAM) with 200
> clients connecting for about 2 months without a crash. However just
> yesterday the database and all the clients hung. When I looked at the
> Mac I'm using as the postgres server it had a window up that said that
> there was no more disk space available to write memory too. I ended up
> having to restart the whole machine. I would like to configure postgres
> so that is does not rely so heavily on disk-based memory but, rather,
> tries to stay within the scope of the 512MB of physical memory in the
> Mac.
>
> Am I correct in thinking that lowering that value of shared_buffers in
> postgresql.conf will reduce the amount of disk space that is swapped
> for memory?
>
> I lowered the value from 2000 down to 500. Was that the right thing to
> do or should I have gone the other way? Any other settings I should
> look at? Thanks!

Your shared buffers are almost certainly not the problem here. 2000
shared buffers is only 16 Megs of ram, max. More than likely, the
database filled up the data directory / partition because it wasn't
being vacuumed.

> Your shared buffers are almost certainly not the problem here. 2000
> shared buffers is only 16 Megs of ram, max. More than likely, the
> database filled up the data directory / partition because it wasn't
> being vacuumed.

Yes.

Also check to make sure that some rogue process somewhere isn't filling your
hard disk with some huge log file. I don't remember the UNIX commands
offhand, but you should sudo a search starting in / for all large files, say
> 1GB for instance.

--
Scott Ribe
scott_ribe(at)killerbytes(dot)com
http://www.killerbytes.com/
(303) 665-7007 voice

BTW Joe,

I sent my earlier suggestion to you directly. You might want to talk to your
email admin to find out why your server bounced a perfectly innocuous
message thusly:

<joe_lester(at)sweetwater(dot)com>:
12.47.0.10 failed after I sent the message.
Remote host said: 550 Message Returned: For some reason, your e-mail was
unable to be delivered to Sweetwater. This may be due to a content filter on
our server. If your message is legitimate and contains questionable content,
please remove it and try re-sending. If you feel this is an error, please
contact your Sweetwater Representative or our E-mail Administrator at
1-800-222-4700 x1198 to resolve this issue. We apologize for any
inconvenience this may have caused. #D702

--
Scott Ribe
scott_ribe(at)killerbytes(dot)com
http://www.killerbytes.com/
(303) 665-7007 voice