RE: cdrecord problem

["Creager, Robert S" <CreagRS@LOUISVILLE.STORTEK.COM>]

I would more suspect media isn't really capable of being burned at that
speed, or the drive really isn't capable of writing at that speed, or some
combination of the two, but not a buffer under run.  My experience with
cdrecord is that it will fail if it experiences a buffer under run.

But, if Tom has one of the newer 'burn proof' cd-writers, I believe they
will automatically stop writing if their internal buffer gets less than 15%
(or something like that) full, and wait for it to fill up before continuing
writing.  I've read that the pause in writing can cause problems with some
CD drives, if the cd-writer doesn't pick up correctly on the restart.

Cheers,
Rob

> -----Original Message-----
> From: Chris Albertson [mailto:chrisalbertson90278@yahoo.com] 
> Sent: September 05, 2003 10:48 AM
> To: tdroege2@earthlink.net; tass
> Subject: Re: cdrecord problem
> 
> 
> 
> At first I thought mkisofs might be screwing up.
> but you say the error rate depends on the recording
> speed.  I suspect now that mkiosfs is not feeding
> cdrecord fast enough.  Assuming you have 800MB of free
> space you could try this:
> 
> mkisofs -R -o /foobar/tempfile disk1
> cdrecord -v fs=6m speed=12 dev=3,0 -" /foobar/tempfile
> rm /foobar/tempfile.
> 
> xcdroast may be able to work at 12x or faster because
> it maintains a large buffer between mkisofs and
> cdrecord and lets mkisofs get a good head start before
> staring cdrecord.  You are using a direct pipe. and it
> looks to me like there is a bottle neck in the system.
> 
> Is this an IDE CD-R device and hard disk?  If so that
> could explain it.  IDE device take a huge amount of
> CPU cycles to drive.
>  
> --- Thomas Droege <tdroege2@earthlink.net> wrote:
> > I am writing backup disks with the following (in
> > perl):
> > 
> > system "mkisofs -R disk1 | cdrecord -v fs=6m
> > speed=12 dev=3,0 -";
> > 
> > I just copied this line from the man pages and
> > figures out what the dev
> > should be.
> > 
> > The CD recorder is a 32x device for write.  the sub
> > directory disk1
> > contains 80 ea. 8 megabyte images.  The CDs I am
> > using are rated at 24x.
> > 
> > About once a directory write, one of the files gets
> > written as a directory.
> > It is then unreadable.  At least for me and the
> > utilities that I have
> > tried. The buffer never gets below 97%.  Sometimes
> > it writes garbage as the
> > CD directory.  An ls gets garbage that I can
> > recognize as part of a fits
> > header.  I have tried recording at different speeds.
> >  24x gets mostly
> > garbage.  12x gets about 1 file per 80 file block as
> > a directory.  All but
> > the file shown as a directory are readable by Gimp.
> > The computer is a 1.5
> > Ghz dual processor Athelon.  
> > 
> > I recall seeing this problem using xcdroast in the
> > previous Mandrake 8.1.
> > I am now using 9.0.  
> > 
> > I seem to be able to record perfectly every time
> > from the same directory
> > "on the fly" using xcdroast at 24x (the CDs are
> > rated at 24x).
> > 
> > Has anyone seen this problem and can recommend what
> > I should do?
> > 
> > Tom Droege   
> > 
> > 
> > 
> > 
> > 
> > 
> 
> 
> =====
> Chris Albertson
>   Home:   310-376-1029  chrisalbertson90278@yahoo.com
>   Cell:   310-990-7550
>   Office: 310-336-5189  Christopher.J.Albertson@aero.org
>   KG6OMK
> 
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