Received: from localhost (maia-2.hub.org [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id 0D6479FBA22 for ; Sun, 20 May 2007 18:58:15 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-maia, port 10024) with ESMTP id 42337-01 for ; Sun, 20 May 2007 18:58:01 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 0FA709FB65C for ; Sun, 20 May 2007 18:58:10 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.1/8.14.1) with ESMTP id l4KLtoj0017451; Sun, 20 May 2007 17:55:50 -0400 (EDT) To: "Ralph Mason" cc: "'Richard Huxton'" , pgsql-performance@postgresql.org Subject: Re: Ever Increasing IOWAIT In-reply-to: <005b01c79b1f$20aeb340$620c19c0$@mason@telogis.com> References: <011b01c798d5$141365a0$3c3a30e0$@mason@telogis.com> <464D6DE1.6040001@archonet.com> <005b01c79b1f$20aeb340$620c19c0$@mason@telogis.com> Comments: In-reply-to "Ralph Mason" message dated "Mon, 21 May 2007 08:40:39 +1200" Date: Sun, 20 May 2007 17:55:50 -0400 Message-ID: <17450.1179698150@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200705/386 X-Sequence-Number: 24776 "Ralph Mason" writes: > Ralph Mason wrote: >> We have a database running on a 4 processor machine. As time goes by >> the IO gets worse and worse peeking at about 200% as the machine loads up. >> >> The weird thing is that if we restart postgres it's fine for hours but >> over time it goes bad again. Do you by any chance have stats collection enabled and stats_reset_on_server_start set to true? If so, maybe this is explained by growth in the size of the stats file over time. It'd be interesting to keep an eye on the size of $PGDATA/global/pgstat.stat over a fast-to- slow cycle. regards, tom lane