Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id 4C287650142 for ; Mon, 25 Aug 2008 05:18:40 -0300 (ADT) Received: from postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 05947-08 for ; Mon, 25 Aug 2008 05:18:28 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from yx-out-2324.google.com (yx-out-2324.google.com [74.125.44.28]) by postgresql.org (Postfix) with ESMTP id 506C264FEE1 for ; Mon, 25 Aug 2008 05:18:26 -0300 (ADT) Received: by yx-out-2324.google.com with SMTP id 8so759618yxb.73 for ; Mon, 25 Aug 2008 01:18:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:sender :to:subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references :x-google-sender-auth; bh=q8zawIpPjlFLpBKkkbrpE6RKgrbII1EhM++OmqmdhOU=; b=RntI0MYAzCSLKbodgEwWnsVzg3jc5HNeoF9czJsy10rj6xohpV4mLx84q7ZIzENhL1 dyXHOpIaV8GDqIv5ceoyHGb+151ZhvhIYyrjSJLurIrnhUSrXvIwDW3TjyshlVkH+4/q +pkkXObQ6EHNGI8KPUS4ZeadXMbCo05R4aw2A= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references:x-google-sender-auth; b=fHa5+51/A1t6vPDTRTifrGlRVQwh429K9KYc7DzGGGwxr+0al92dLFBbzpjiuY5uaQ z6vMq2QPA7aZynGLrtwyS3jX1ME7GfNUJBuuZO6GpyzKA2lAbZtr2WAB3g+6OVWGETbY NWgtzKGbuI0aFxXyxHetksX+AQDVZqEKTh40Q= Received: by 10.114.182.1 with SMTP id e1mr3064851waf.143.1219652304499; Mon, 25 Aug 2008 01:18:24 -0700 (PDT) Received: by 10.114.106.19 with HTTP; Mon, 25 Aug 2008 01:18:24 -0700 (PDT) Message-ID: <88daf38c0808250118j571bbd98sbade235a141984b4@mail.gmail.com> Date: Mon, 25 Aug 2008 10:18:24 +0200 From: "Alexander Staubo" To: "Scott Carey" Subject: Re: Identifying the nature of blocking I/O Cc: pgsql-performance In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080822115243.GA10981@hyperion.scode.org> <48B1FD1A.7040807@postnewspapers.com.au> X-Google-Sender-Auth: b8c7b37e255c3d5d X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200808/321 X-Sequence-Number: 31202 On Mon, Aug 25, 2008 at 3:34 AM, Scott Carey wrote: > DTrace is available now on MacOSX, Solaris 10, OpenSolaris, and FreeBSD. > Linux however is still in the dark ages when it comes to system monitoring, > especially with I/O. While that's true, newer 2.6 kernel versions at least have I/O accounting built in, something which only used to be available through the "atop" accounting kernel patch: $ cat /proc/22785/io rchar: 31928 wchar: 138 syscr: 272 syscw: 4 read_bytes: 0 write_bytes: 0 cancelled_write_bytes: 0 Alexander.