From owner-freebsd-questions Fri May 18 10:48: 2 2001 Delivered-To: freebsd-questions@freebsd.org Received: from mr200.netcologne.de (mr200.netcologne.de [194.8.194.109]) by hub.freebsd.org (Postfix) with ESMTP id 28DFB37B43F for ; Fri, 18 May 2001 10:47:58 -0700 (PDT) (envelope-from pherman@frenchfries.net) Received: from husten.security.at12.de (dial-213-168-88-220.netcologne.de [213.168.88.220]) by mr200.netcologne.de (Mirapoint) with ESMTP id AFS62869; Fri, 18 May 2001 19:47:54 +0200 (CEST) Received: from localhost (localhost.security.at12.de [127.0.0.1]) by husten.security.at12.de (8.11.3/8.11.3) with ESMTP id f4IHlhF41387; Fri, 18 May 2001 19:47:43 +0200 (CEST) (envelope-from pherman@frenchfries.net) Date: Fri, 18 May 2001 19:47:43 +0200 (CEST) From: Paul Herman To: Kevin Oberman Cc: "Jon O." , Subject: Re: FreeBSD benchmark question In-Reply-To: <200105181727.f4IHRCc02845@ptavv.es.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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 On Fri, 18 May 2001, Kevin Oberman wrote: > Another significant issue if you are using IDE disk is write cache. It > is currently turned off by default to prevent possible data loss. You > might want to test with it on (or turn it off in Linux, if you can). The way Jon O. described the run ("genetic searches"), it sounded like it wasn't doing much writing to the disk, so write cache, softupdates, etc. will do little help if it's just reading data from a disk. It sounded like it was I/O bound and profited from a large disk cache (read "reading from disk".) I'm pretty sure Linux caches directory entries but FreeBSD doesn't by default. Be sure you have: sysctl -w vfs.vmiodirenable=1 enabled. There was some debate about whether or not this should be turned on by default, and the general consensus was that it should. With vmiodirenable your disk cache will work Just Like Linux. ;-) -Paul. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message