PostgreSQL uses more memory on 6.1?

[Bill Moran]

On Tue, 23 May 2006 15:37:25 -0500
Kirk Strauser <kirk at strauser.com> wrote:

> I just upgraded from 6-STABLE as of 2006-02-18 to 6-STABLE as of 2006-05-21, 
> and was surprised to find that PostgreSQL wouldn't start because it 
> couldn't allocate enough shared memory.  Thing is, I didn't make a single 
> hardware change during the reboot and didn't upgrade any ports on the 
> machine.
> 
> My emergency fix was to edit postgresql.conf to change shared_buffers from 
> 8192 to 2048.  Unfortunately, that seems to be hurting performance - I'm 
> getting annoying deadlocks at 4AM whenever multiple daemons start their 
> overnight batch runs.
> 
> Has anyone else seen this behavior when upgrading from 6.0 to 6.1?  Any 
> ideas for a fix?
> 
> I apologize for not having a logfiles, but I was pretty much in a panic to 
> get it back up and running ASAP and didn't think about it until it was too 
> late.

Quick patch:
Use sysctl to bump up kern.ipc.* values as needed (probably shmmax)
You should then be able to return your postgresql.conf values to
whatever performs well

Ultimate fix:
Figure out why these values changed.  Most likely the result of a
different kernel config file.  Either put the workable values in a
kernel config that will persist across upgrades, or put them in
/etc/sysctl.conf so you don't lose them.

-- 
Bill Moran
Collaborative Fusion Inc.

****************************************************************
IMPORTANT: This message contains confidential information and is
intended only for the individual named. If the reader of this
message is not an intended recipient (or the individual
responsible for the delivery of this message to an intended
recipient), please be advised that any re-use, dissemination,
distribution or copying of this message is prohibited. Please
notify the sender immediately by e-mail if you have received
this e-mail by mistake and delete this e-mail from your system.
E-mail transmission cannot be guaranteed to be secure or
error-free as information could be intercepted, corrupted, lost,
destroyed, arrive late or incomplete, or contain viruses. The
sender therefore does not accept liability for any errors or
omissions in the contents of this message, which arise as a
result of e-mail transmission.
****************************************************************