From owner-freebsd-scsi Wed Dec 10 00:52:26 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id AAA29414 for freebsd-scsi-outgoing; Wed, 10 Dec 1997 00:52:26 -0800 (PST) (envelope-from owner-freebsd-scsi) Received: from sax.sax.de (sax.sax.de [193.175.26.33]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id AAA29401 for ; Wed, 10 Dec 1997 00:52:20 -0800 (PST) (envelope-from j@uriah.heep.sax.de) Received: (from uucp@localhost) by sax.sax.de (8.8.8/8.8.8) with UUCP id JAA05772 for scsi@FreeBSD.ORG; Wed, 10 Dec 1997 09:52:16 +0100 (CET) (envelope-from j@uriah.heep.sax.de) Received: (from j@localhost) by uriah.heep.sax.de (8.8.8/8.8.5) id JAA07742; Wed, 10 Dec 1997 09:46:20 +0100 (MET) Message-ID: <19971210094619.54824@uriah.heep.sax.de> Date: Wed, 10 Dec 1997 09:46:19 +0100 From: J Wunsch To: scsi@FreeBSD.ORG Subject: Re: Questions about mt and SCSI subsystem Reply-To: Joerg Wunsch References: <199712100705.XAA22478@math.berkeley.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.88 In-Reply-To: <199712100705.XAA22478@math.berkeley.edu>; from Dan Strick on Tue, Dec 09, 1997 at 11:05:33PM -0800 X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E Sender: owner-freebsd-scsi@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk As Dan Strick wrote: > For drives > that are not capable of overwriting EOF marks, I favor the convention > that a single EOF mark (with no backspace) be written in these > circumstances and that a double EOF mark be written before rewinds > (even though this may inconvenience lazy programmers who don't think > ahead). Still, this would break appending to the tape, where it leaves the double EOF. > The convention that a raw tape driver return a single zero length > read to mark EOF is very ancient and should be respected because it > is so darn useful. Right he is! Note that this convention doesn't only apply to tape devices, it applies to any Unix device. It was handled rather sloppy in FreeBSD, it's not that long ago that i've fixed the floppy disk driver's EOF handling. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)