Re: cdrecord problem

[Chris Albertson <chrisalbertson90278@yahoo.com>]

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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