Skip site navigation (1) Skip section navigation (2)

Re: SAN performance mystery

From: Jeff Trout <threshar(at)torgo(dot)978(dot)org>
To: Tim Allen <tim(at)proximity(dot)com(dot)au>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: SAN performance mystery
Date: 2006-06-16 17:58:31
Message-ID: 922914D7-46ED-4623-905A-C56058551905@torgo.978.org (view raw or flat)
Thread:
Lists: pgsql-performance
On Jun 16, 2006, at 5:11 AM, Tim Allen wrote:
>
> One curious thing is that some postgres backends seem to spend an  
> inordinate amount of time in uninterruptible iowait state. I found  
> a posting to this list from December 2004 from someone who reported  
> that very same thing. For example, bringing down postgres on the  
> customer box requires kill -9, because there are invariably one or  
> two processes so deeply uninterruptible as to not respond to a  
> politer signal. That indicates something not quite right, doesn't it?
>

Sounds like there could be a driver/array/kernel bug there that is  
kicking the performance down the tube.
If it was PG's fault it wouldn't be stuck uninterruptable.

--
Jeff Trout <jeff(at)jefftrout(dot)com>
http://www.dellsmartexitin.com/
http://www.stuarthamm.net/




In response to

Responses

pgsql-performance by date

Next:From: Stefan KaltenbrunnerDate: 2006-06-16 18:14:47
Subject: Re: Test request for Stats collector performance improvement
Previous:From: Josh BerkusDate: 2006-06-16 17:01:56
Subject: Re: Sun Donated a Sun Fire T2000 to the PostgreSQL community

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group