From owner-freebsd-questions Thu Aug 30 10:26:29 2001 Delivered-To: freebsd-questions@freebsd.org Received: from ns1.avatar.com (ns1.avatar.com [199.33.206.1]) by hub.freebsd.org (Postfix) with ESMTP id E9AC237B405 for ; Thu, 30 Aug 2001 10:26:26 -0700 (PDT) (envelope-from kory@avatar.com) Received: from tomcat (tomcat.avatar.com [199.33.206.20]) by ns1.avatar.com (8.12.0.Beta8/8.12.0.Beta8) with SMTP id f7UHMcUM007363; Thu, 30 Aug 2001 10:22:38 -0700 (PDT) From: "Kory Hamzeh" To: "Mike Meyer" Cc: Subject: RE: Performance tuning results Date: Thu, 30 Aug 2001 10:24:51 -0700 Message-ID: <003b01c13178$ad44fa60$14ce21c7@avatar.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook 8.5, Build 4.71.2173.0 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 In-Reply-To: <15245.63001.898491.751110@guru.mired.org> Importance: Normal Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > -----Original Message----- > From: owner-freebsd-questions@FreeBSD.ORG > [mailto:owner-freebsd-questions@FreeBSD.ORG]On Behalf Of Mike Meyer > > What's interesting is that IDE write caching helped more than the > > softupdates. > > Why is that interesting? Softupdates caches things in the system > memory to try and improve performance in a reliable manner. IDE disk > caching caches things in the disks memory without worrying about > reliability. One would expect the more reliable mechanism to be > slower. Because I assume that the system buffer cache is larger than the drive's buffer cache. > > If you really want the extra speed - and don't care about reliability > - you can mount your file systems async, softupdates off. If soft > udpates are on, the async flag to mount is quietly ignored. That > caches data in the system memory without regard to reliability just > like the IDE disk cache does. > Why is IDE write caching less reliable than softupdates? They both basically do the same thing: delay the write. Kory To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message