Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id CC755650030 for ; Mon, 8 Sep 2008 11:02:41 -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 27266-06 for ; Mon, 8 Sep 2008 11:02:31 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-gx0-f17.google.com (mail-gx0-f17.google.com [209.85.217.17]) by postgresql.org (Postfix) with ESMTP id C78D864FCFA for ; Mon, 8 Sep 2008 11:02:30 -0300 (ADT) Received: by gxk10 with SMTP id 10so7778902gxk.19 for ; Mon, 08 Sep 2008 07:02:28 -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:to :subject:cc:in-reply-to:mime-version:content-type:references; bh=71Oi2Ki2xzrQL+ZzhzvJ6A4oq0H1ymB4WkVNzORJjP4=; b=cRWhweogI8LbWMILt3BgbUwg0YdQoUqnX9P741M7uQ2Aink4SOrZwYoTn7msOkPL1T zrYlDZheyIFkdmLWEHwY7BzjQVKtvJZYt/Ox20Ca0oP/3ta9eiS6ZUpsqlXmLhJkZhbd YKdifqGXwiyQJF3AgwwOQ6qiElNmcXYGEdN5I= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:references; b=icWCS2ezZgGYP3odWF7bmnV9GPPMv5/32Ac//YcxNQjWO1peHGfV1uUs/HtlU7XKcQ rBuSgI+imNJCUZ6fQiRcwHz7m/z2AALkboP1q3BcY3C+jQ7cgxReiATrvrm/LxdbCmu2 M0EpPFTa4CuOU9Lw+7qlHpOzyfEiexjJ4X9RQ= Received: by 10.114.176.1 with SMTP id y1mr12373962wae.118.1220882547372; Mon, 08 Sep 2008 07:02:27 -0700 (PDT) Received: by 10.114.120.19 with HTTP; Mon, 8 Sep 2008 07:02:27 -0700 (PDT) Message-ID: Date: Mon, 8 Sep 2008 10:02:27 -0400 From: "Nikolas Everett" To: "Bruce Momjian" Subject: Re: SAN and full_page_writes Cc: pgsql-performance@postgresql.org In-Reply-To: <200809061946.m86JkeS01341@momjian.us> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_56881_10396036.1220882547374" References: <200809061946.m86JkeS01341@momjian.us> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.001 tagged_above=0 required=5 tests=HTML_MESSAGE=0.001 X-Spam-Level: X-Archive-Number: 200809/83 X-Sequence-Number: 31396 ------=_Part_56881_10396036.1220882547374 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Thanks for pointing that out Bruce. NetApp has a 6 page PDF about NetApp and databases. On page 4: As discussed above, reads and writes are unconditionally atomic to 64 KB. While reads or writes may fail for a number of reasons (out of space, permissions, etc.), the failure is always atomic to 64 KB. All possible error conditions are fully evaluated prior to committing any updates or returning any data to the database.