Received: from localhost (wm.hub.org [200.46.204.128]) by postgresql.org (Postfix) with ESMTP id 361B59FB2C0 for ; Fri, 10 Nov 2006 14:54:52 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.128]) (amavisd-new, port 10024) with ESMTP id 10001-02 for ; Fri, 10 Nov 2006 18:54:44 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey- Received: from floppy.pyrenet.fr (floppy.pyrenet.fr [194.116.145.2]) by postgresql.org (Postfix) with ESMTP id A91209FA196 for ; Fri, 10 Nov 2006 14:54:14 -0400 (AST) Received: by floppy.pyrenet.fr (Postfix, from userid 106) id B691B30E1C; Fri, 10 Nov 2006 19:54:11 +0100 (MET) From: Ron Mayer X-Newsgroups: pgsql.performance Subject: Lying drives [Was: Re: Which OS provides the _fastest_ PostgreSQL performance?] Date: Fri, 10 Nov 2006 10:54:01 -0800 Organization: Hub.Org Networking Services Lines: 25 Message-ID: <4554CAC9.3000104@cheapcomplexdevices.com> References: <1162845613.083003.34870@e3g2000cwe.googlegroups.com> <454fa7c5$0$625$5a6aecb4@news.aaisp.net.uk> <1162858497.14060.0@proxy02.news.clara.net> <1162863350.101851.181650@k70g2000cwa.googlegroups.com> <1162887032.14110.0@damia.uk.clara.net> <1162920135.543539.118390@h54g2000cwb.googlegroups.com> <2cl4h.1236$Es5.713@trnddc07> <1162995009.842121.125840@k70g2000cwa.googlegroups.com> <1163016362.882752.14140@m7g2000cwm.googlegroups.com> <06E4h.5421$Lt4.2413@trnddc08> <1163084338.373159.99280@h54g2000cwb.googlegroups.com> <1163171668.837184.161080@e3g2000cwe.googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@news.hub.org Cc: Ron Mayer To: toby User-Agent: Thunderbird 1.5.0.7 (X11/20060927) In-Reply-To: <1163171668.837184.161080@e3g2000cwe.googlegroups.com> To: pgsql-performance@postgresql.org X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200611/95 X-Sequence-Number: 21865 toby wrote: > > That's not quite what I meant by "trust". Some drives lie about the > flush. Is that really true, or a misdiagnosed software bug? I know many _drivers_ lie about flushing - for example EXT3 on Linux before early 2005 "did not have write barrier support that issues the FLUSH CACHE (IDE) or SYNCHRONIZE CACHE (SCSI) commands even on fsync" according to the writer of the Linux SATA driver.[1] This has the same effect of having a lying disk drive to any application code (including those designed to test for lying drives), but is instead merely a software bug. Does anyone have an example of an current (on the market so I can get one) drive that lies about sync? I'd be interested in getting my hands on one to see if it's a OS-software or a drive-hw/firmware issue. [1] http://hardware.slashdot.org/comments.pl?sid=149349&cid=12519114