Fw: [Sussex] Problem writing image to CD

[Stephen Williams]

On Sun, 2005-10-09 at 20:30 +0100, Brendan Whelan wrote:
> Hi,
> 
> I have looked up the spec for the CDRW combo drive - Toshiba Samsung claim
> 24x when writing to a CDR and 10x when writing to a CDRW.
> So I could take my writing speed up from 4x to 10x.
> 
> Brendan
> ----- Original Message -----
> From: "Brendan Whelan" <b_whelan at mistral.co.uk>
> To: <sdp.williams at btinternet.com>; "LUG email list for the Sussex Counties"
> <sussex at mailman.lug.org.uk>
> Sent: Sunday, October 09, 2005 3:55 PM
> Subject: Re: [Sussex] Problem writing image to CD
> 
> 
> > Thanks for the responses.
> >
> > I don't have the system powered up at the moment.
> > I had wondered about some sort of time out problem -where can I find the
> > settings for apm or acpi?
> > I am only recording at x4 on a modern 3GHz system - is there a way of
> > finding out the maximum speed at which I can record?
> >

I'd look in the BIOS first - there may be an option to power down the
drives in BIOS Power Management. Beyond that I'd suggest you talk to
Steve Dobson for advice on linux apm and acpi.

I find some CD-RW drives only write at lower speeds than the drive spec
and disk spec would suggest. I'm not sure why this is.

Steve W.


> > Thanks,  Brendan
> > > down
> > ----- Original Message -----
> > From: "Stephen Williams" <sdp.williams at btinternet.com>
> > To: "LUG email list for the Sussex Counties" <sussex at mailman.lug.org.uk>
> > Sent: Sunday, October 09, 2005 12:50 PM
> > Subject: Re: [Sussex] Problem writing image to CD
> >
> >
> > > On Fri, 2005-10-07 at 21:28 +0100, Brendan Whelan wrote:
> > > > Hello,
> > > >
> > > > I have created a backup shell script which exports a database, gathers
> > > > files, creates a CD image file and then writes it to a CD.
> > > > The shell script is then scheduled to run during the night. There are
> > > > a pair of, logically identical, systems one a Dell tower and the other
> > > > a Dell rack mountable servers. (Fedora Core 3 is used on both
> > > > systems.) The shell script works perfectly on the tower system but on
> > > > the rack mounted machine the CD writing fails. The image to be copied
> > > > is only about 360Mb, I have used different manufacturers CDs but the
> > > > problem persists. I changed the CD drive but the problem persists.
> > > >
> > > > I have taken an image copy of the offending system and placed it my
> > > > test system with the same type of CD writer which is in the rack
> > > > mountable system.
> > > > To simplify the problem I created a shell script which just
> > > > contains the line which writes to the CD.  When I run the script in a
> > > > terminal window it works. When I run it as a cron job it fails. The
> > > > led on the CD writer flashes for a number of minutes and then goes on.
> > > > The CD cannot be unmounted and the only way to extract the CD is to
> > > > either power the system down and back up or to use a paper clip to
> > > > release the CD drawer. (As an aside small image files can be written
> > > > to the CD using a cron job.)
> > > >
> > > > Any suggestions as to what might be causing the problem or how I could
> > > > find out more information.
> > >
> > > My suspicions centre around power saving. Is apm or acpi set to power
> > > down the CD-RW in the rackmount box and not in the tower box for
> > > example.  Perhaps the user account under which the cron job is run needs
> > > sufficient authority to be able to prevent power down signals from
> > > affecting the CD-RW when a job is in progress? Might be something worth
> > > investigating.
> > >
> > > Steve W.
> > >
> > >
> > > >
> > > > Thanks, Brendan
> > > > _______________________________________________
> > > > Sussex mailing list
> > > > Sussex at mailman.lug.org.uk
> > > > Sussex LUG Website: http://www.sussex.lug.org.uk/
> > > > http://mailman.lug.org.uk/mailman/listinfo/sussex
> > >
> > >
> > > _______________________________________________
> > > Sussex mailing list
> > > Sussex at mailman.lug.org.uk
> > > Sussex LUG Website: http://www.sussex.lug.org.uk/
> > > http://mailman.lug.org.uk/mailman/listinfo/sussex
> > >
> > >
> >
> >
> >
> > _______________________________________________
> > Sussex mailing list
> > Sussex at mailman.lug.org.uk
> > Sussex LUG Website: http://www.sussex.lug.org.uk/
> > http://mailman.lug.org.uk/mailman/listinfo/sussex
> >
> >
> 
> 
> 
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