From owner-freebsd-fs Fri Jan 31 11:23:55 2003 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 2D45237B401 for ; Fri, 31 Jan 2003 11:23:54 -0800 (PST) Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4485F43F75 for ; Fri, 31 Jan 2003 11:23:53 -0800 (PST) (envelope-from phk@freebsd.org) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.6/8.12.6) with ESMTP id h0VJNq4W025201; Fri, 31 Jan 2003 20:23:52 +0100 (CET) (envelope-from phk@freebsd.org) To: Steve Byan Cc: freebsd-fs@freebsd.org, tech-kern@netbsd.org Subject: Re: DEV_B_SIZE From: phk@freebsd.org In-Reply-To: Your message of "Fri, 31 Jan 2003 14:06:11 EST." <1010FEB6-354F-11D7-B26B-00306548867E@maxtor.com> Date: Fri, 31 Jan 2003 20:23:52 +0100 Message-ID: <25200.1044041032@critter.freebsd.dk> 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 In message <1010FEB6-354F-11D7-B26B-00306548867E@maxtor.com>, Steve Byan writes : >> Not broken any worse than because of write-caching. > >Agreed, but IDEMA is proposing to do this to SCSI drives, too. We've seen broken caching on SCSI as well, but not recently I think :-) >But if someone were to plug a new 4K-block disk into a system compiled >to use 512 byte block disks, and the SCSI interface were faked to make >it appear that the disk could read and write 512-byte blocks, then what >happens? IDEMA's notion is that faking 512-byte logical size is good >enough to get new disks to work in systems running legacy code. My fear >is that it is not so simple. If plug a 4k sector disk into a system which doesn't know how to find out that the drive really is 4k sectors, then you will increase the window for lossage. >> The thing we really need is working tagged-queing... > >Since I believe tagged-queuing works in SCSI, I assume you are asking >for it in ATA? Or is there some feature missing from SCSI >tagged-queuing that you'd like to see? Yes, I was talking ATA there. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message