From owner-freebsd-scsi Mon Nov 13 1:12: 8 2000 Delivered-To: freebsd-scsi@freebsd.org Received: from antholoma.wanadoo.fr (smtp-abo-4.wanadoo.fr [193.252.19.153]) by hub.freebsd.org (Postfix) with ESMTP id 3479A37B479; Mon, 13 Nov 2000 01:12:02 -0800 (PST) Received: from hautmedoc.dockes.com (164.138.104.90) by antholoma.wanadoo.fr; 13 Nov 2000 10:11:58 +0100 Received: (from dockes@localhost) by hautmedoc.dockes.com (8.9.3/8.9.3) id KAA46032; Mon, 13 Nov 2000 10:11:57 +0100 (MET) From: Jean-Francois Dockes MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <14863.45144.972743.315716@hautmedoc.dockes.com> Date: Mon, 13 Nov 2000 10:11:52 +0100 (MET) To: David Kelly Cc: =?iso-8859-1?q?Graham=20Guttocks?= , freebsd-scsi@FreeBSD.ORG, freebsd-multimedia@FreeBSD.ORG Subject: Re: my first coaster with cdrecord/FreeBSD :-( In-Reply-To: <200011130258.eAD2weS69470@grumpy.dyndns.org> References: <20001113021031.75150.qmail@web10308.mail.yahoo.com> <200011130258.eAD2weS69470@grumpy.dyndns.org> X-Mailer: VM 6.75 under 20.4 "Emerald" XEmacs Lucid Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org David Kelly writes: > =?iso-8859-1?q?Graham=20Guttocks?= writes: > > "Kenneth D. Merry" wrote: > > > > > This looks like a bad block on the CD. Thus the reason it worked > > > when you tried again with a new CD. (Which is probably the right > > > approach to take to fix the problem.) > > > > Uhm, ok. I guess I find this hard to swallow since this was a > > high-quality CD-R, brand-new from its case. > > In previous employment we were going thru about 500 CD-R blanks/year. > One bad out of 12 isn't good, but also isn't a large enough sample size > to say. Some lots of blanks are simply lemons. Its not as if they can > do 100% testing from the factory. :-) My current employer went through >1.5 million discs this year :) In my experience, pure optical media problems are relatively infrequent, except for the already mentioned case of the bit of plastic stuck to the disc by static (or the fingerprints). The most probable situation when you see a transient writing failure is that you have a slightly marginal recorder meeting slightly marginal media. The recorder will work fine on perfect media, and other media from the marginal batch will work well on a healthy recorder. This makes for very difficult problem solving. When you are lucky, the recorder will go completely south a little after, and you'll stop pulling your hair... Of course, there are also cases of really bad (out of spec) media, just to make for a richer fun. But keep smiling: you are working with 1$ discs. It was much more fun a few years ago, when trying to diagnose 12" optical media that costed around $1000, on recorders in the 20,000 $ range, that would fail much more than the current cd burners :) Especially on big banking customer sites... -- Jean-Francois Dockes jean-francois.dockes@wanadoo.fr To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message