Re: [PERFORM] why does swap not recover?

2010-03-30 Thread Robert Haas
On Fri, Mar 26, 2010 at 7:57 PM, Richard Yen wrote: > Note that it is constantly paging in, but never paging out.  This would > indicate that it's constantly reading from swap, but never writing out to it. >  Why would postgres do this? (postgres is pretty much the only thing running > on this

Re: [PERFORM] why does swap not recover?

2010-03-29 Thread Josh Berkus
On 3/26/10 4:57 PM, Richard Yen wrote: > I'm planning on lowering the shared_buffers to a more sane value, like 25GB > (pgtune recommends this for a Mixed-purpose machine) or less (pgtune > recommends 14GB for an OLTP machine). However, before I do this (and > possibly resolve the issue), I was

Re: [PERFORM] why does swap not recover?

2010-03-27 Thread Richard Yen
On Mar 26, 2010, at 5:25 PM, Scott Carey wrote: > Linux until recently does not account for shared memory properly in its swap > 'aggressiveness' decisions. > Setting shared_buffers larger than 35% is asking for trouble. > > You could try adjusting the 'swappiness' setting on the fly and seeing

Re: [PERFORM] why does swap not recover?

2010-03-26 Thread Craig James
On 3/26/10 4:57 PM, Richard Yen wrote: Hi everyone, We've recently encountered some swapping issues on our CentOS 64GB Nehalem machine, running postgres 8.4.2. Unfortunately, I was foolish enough to set shared_buffers to 40GB. I was wondering if anyone would have any insight into why the sw

Re: [PERFORM] why does swap not recover?

2010-03-26 Thread Scott Carey
On Mar 26, 2010, at 4:57 PM, Richard Yen wrote: > Hi everyone, > > We've recently encountered some swapping issues on our CentOS 64GB Nehalem > machine, running postgres 8.4.2. Unfortunately, I was foolish enough to set > shared_buffers to 40GB. I was wondering if anyone would have any insigh

Re: [PERFORM] why does swap not recover?

2010-03-26 Thread Scott Marlowe
On Fri, Mar 26, 2010 at 5:57 PM, Richard Yen wrote: > Hi everyone, > > We've recently encountered some swapping issues on our CentOS 64GB Nehalem What version Centos? How up to date is it? Are there any other settings that aren't defaults in things like /etc/sysctl.conf? -- Sent via pgsql-per

[PERFORM] why does swap not recover?

2010-03-26 Thread Richard Yen
Hi everyone, We've recently encountered some swapping issues on our CentOS 64GB Nehalem machine, running postgres 8.4.2. Unfortunately, I was foolish enough to set shared_buffers to 40GB. I was wondering if anyone would have any insight into why the swapping suddenly starts, but never recover