From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: mismatch_cnt again Date: Tue, 17 Nov 2009 00:19:40 -0500 Message-ID: References: <4AF4C247.6050303@eyal.emu.id.au> <4AF4D323.6020108@panix.com> <4AF5268D.60900@eyal.emu.id.au> <4877c76c0911070008m789507f8h799d419287740ca5@mail.gmail.com> <87tyx6tpcb.fsf@frosties.localdomain> <4AF58B20.3000409@redhat.com> <87iqdlaujb.fsf@frosties.localdomain> <4AF74B61.6000102@rabbit.us> <20091109185632.GA2723@lazy.lzy> <73ebdcee169f46611d411755f9aaca5b.squirrel@neil.brown.name> <20091109215443.GA4143@lazy.lzy> <4AF92DBD.5010102@rabbit.us> <4AFC8EC5.6060400@tmr.com> <4AFEE283.9040702@tmr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <4AFEE283.9040702@tmr.com> (Bill Davidsen's message of "Sat, 14 Nov 2009 12:01:55 -0500") Sender: linux-raid-owner@vger.kernel.org To: Bill Davidsen Cc: "Martin K. Petersen" , Peter Rabbitson , NeilBrown , Piergiorgio Sartor , Goswin von Brederlow , Doug Ledford , Michael Evans , Eyal Lebedinsky , linux-raid list List-Id: linux-raid.ids >>>>> "Bill" == Bill Davidsen writes: >> FWIW, databases on raw disk have gone out of fashion. But it is true >> that applications that do direct I/O need to avoid updating buffers >> in flight. >> Bill> May have gone out of fashion in new applications (I'm not sure I Bill> agree, but as a talking point), I don't believe Oracle supports it anymore. ASM solves this and several other problems. Bill> but there are tons of old apps which are not going to be updated Bill> any time soon, and any number of libraries which mmap stuff and Bill> effect multiple applications. We'll just unmap the page while it's being written out. -- Martin K. Petersen Oracle Linux Engineering