Burning CDs on FreeBSD 7.2

Polytropon freebsd at edvax.de
Thu Jun 17 06:01:24 UTC 2010

On Wed, 16 Jun 2010 03:03:02 -0700 (PDT), Mark Terribile <materribile at yahoo.com> wrote:
> Thanks to Jerrymc and Polyoptron.  Things are working, sort of. 
> I'm using the atapicam/cdrecord solution.  But when I do a dd
> read to verify the write, the read ends on an I/O error rather
> than an EOF.  (I'm not sure that this problem is new.)  There
> is a very long delay between dd's report and the program end
> (delay on close?)  And sometimes the eject command after the
> dd locks up and eventually fails.  There are plenty of console
> messages, including READ_BIG retrying, READ_BIG timed out,
> TEST_UNIT_READY freeing zombie taskqueue request, and PREVENT_ALLOW
> taskqueue timeout - compiing request directly . 

I start wondering if this may be due to a defective drive,
or wrong cable, or even through DMA incompatibilites...

Instead of using dd (have you made sure to use the correct
block size?) try using readcd (comes with cdrecord); see
"man cdrecord" for details and examples.

> This is definitely NOT reliable enough to put into a script
> (which would make handling the many file names more reliable).


> cdrecord reports
> -----------------------------------
> scsidev: '4,0,0'
> scsibus: 4 target: 0 lun: 0
> SCSI buffer size: 64512
> Track 01: Total bytes read/written: 103874560/103874560 (50720 sectors).
> Writing  time:   41.290s
> Average write speed  20.8x.

Try to force a lower value, maybe drive and discs are not compatible.
With -speed 8 it should be "slow enough" and "fast enough" for a test.
You can use -prcap to find out what the drive tells cdrecord about

> I would be grateful for any clues about what is still wrong here.

I'd slowly expect a defective drive...

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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