From owner-freebsd-fs Wed Nov 13 0:55:53 2002 Delivered-To: freebsd-fs@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A66B037B401 for ; Wed, 13 Nov 2002 00:55:52 -0800 (PST) Received: from pohoda.cz (pohoda.pohoda.cz [194.228.111.151]) by mx1.FreeBSD.org (Postfix) with SMTP id 11C7443E7B for ; Wed, 13 Nov 2002 00:55:51 -0800 (PST) (envelope-from plusik@pohoda.cz) Received: (qmail 13182 invoked from network); 13 Nov 2002 08:55:51 -0000 Received: from plusik@pohoda.cz by pohoda.cz by uid 500 with qmail-scanner-1.15 ( Clear:. Processed in 0.048324 secs); 13 lis 2002 08:55:51 -0000 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 13 Nov 2002 08:55:51 -0000 Date: Wed, 13 Nov 2002 09:55:51 +0100 (CET) From: Tomas Pluskal To: Terry Lambert Cc: Subject: Re: seeking help to rewrite the msdos filesystem Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org > > This has more to do with sequential access. Technically, you can > read a FAT cluster at a time instead of an FS block at a time, and > you will achieve some multiplier on sequential access, but you will > find that under load, that the fault rate for blocks will go up. When I read from my ZIP drive, according to iostat the request size is 2KB. When I run dd with 2KB request size: # dd if=/dev/afd0 of=/dev/null bs=2048 count=100 100+0 records in 100+0 records out 204800 bytes transferred in 2.127448 secs (96266 bytes/sec) If I understand this right, I can never get faster then 96KB/s with sequential access, when using 2KB requests ? It is quite slow :) Tomas Pluskal To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message