From owner-freebsd-hackers Tue Oct 2 9:33:49 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from elvis.mu.org (elvis.mu.org [216.33.66.196]) by hub.freebsd.org (Postfix) with ESMTP id B52AE37B409 for ; Tue, 2 Oct 2001 09:33:46 -0700 (PDT) Received: by elvis.mu.org (Postfix, from userid 1192) id A7F6781D01; Tue, 2 Oct 2001 11:33:46 -0500 (CDT) Date: Tue, 2 Oct 2001 11:33:46 -0500 From: Alfred Perlstein To: Egervary Gergely Cc: freebsd-hackers@freebsd.org Subject: Re: newbie question: filesystem i/o Message-ID: <20011002113346.D59854@elvis.mu.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from mauzi@faber.poli.hu on Tue, Oct 02, 2001 at 05:59:48PM +0200 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Egervary Gergely [011002 11:00] wrote: > hi hackers, > > I'm quite new to FreeBSD but not in UN*X, please let me ask a question: > > I wonder that the filesystem performance under FreeBSD is so great. I'm > doing disk-to-disk file copies, like ``dd if=file1 of=file2 bs=64k'' and > the performance is much better than on other unices. Other systems use > 16k or 64k (or whatever MAXBSIZE is set to) chunks for sequential i/o, and > the disk seeks like an evil. On FreeBSD, the disk seeks _much_ less. > > probably FreeBSD is re-blocking the (contigous?) chunks, and does i/o with > huge blocks like several megabytes? How is it done technically? Is it the > filesystem, or the VM? > > could someone enlighten me please? :) Hmm.. http://shop.barnesandnoble.com/booksearch/isbnInquiry.asp?isbn=0201549794 Also, you'll want to clarify what you mean by "most unicies", you can't compare apples and cold fusion, at least give us an orange, ok? :) -- -Alfred Perlstein [alfred@freebsd.org] 'Instead of asking why a piece of software is using "1970s technology," start asking why software is ignoring 30 years of accumulated wisdom.' To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message