[TriLUG] why can't I dd an audio CD?

[Nick Goldwater]

Did you unmount the CD before trying to DD?
Nick

----- "Joseph Mack NA3T" <jmack at wm7d.net> wrote:

| From: "Joseph Mack NA3T" <jmack at wm7d.net>
| To: trilug at trilug.org
| Sent: Thursday, December 25, 2008 8:41:59 PM GMT -05:00 US/Canada Eastern
| Subject: [TriLUG] why can't I dd an audio CD?
|
| I just tried dd'ing some audio CDs. The audio CDs behave 
| normally under Linux (can mount -t cdfs and see all the wav 
| files, and can copy with cdda2wav), but dd=/dev/cdrom 
| of=foo.out fails with a bad read on the first sector. dd on 
| an iso9660 (data) cdrom works as expected.
| 
| Google isn't terribly helpful, apart from confirming that dd 
| fails for everyone on audio CDs. I found postings which said
| 
| o audio CDs have a single spiral track (one posting) (but 
| counter to this, cdda2wav sees the disks as sectors)
| 
| o dd doesn't read everything and in particular doesn't work 
| for audio tracks
| 
| So dd fails, but I don't know why dd fails. I would have 
| thought a CD just a pile of bits like a regular hard disk.
| 
| What am I missing?
| 
| Thanks Joe
| 
| -- 
| Joseph Mack NA3T EME(B,D), FM05lw North Carolina
| jmack (at) wm7d (dot) net - azimuthal equidistant map
| generator at http://www.wm7d.net/azproj.shtml
| Homepage http://www.austintek.com/ It's GNU/Linux!
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