Subject: Okay, now I'm stumped.
To: None <>
From: Peter Seebach <>
List: current-users
Date: 05/25/2000 11:53:50
Would someone with some scratch space kindly verify whether or not I'm

	$ dd if=/dev/cd0a of=cd

I believe this should come up with a CD image.

It comes up with something 4 times the size of a CD image.

I am assuming this is because CD's really use 2048-blocks, not 512-blocks,
but "disklabel cd0" reports partition sizes in 512-blocks.

Thus, given the 1.4.2 CD I picked up at Comdex, disklabel says:

  bytes/sector: 2048
  sectors/track: 100
  tracks/cylinder: 1
  sectors/cylinder: 100
  cylinders: 2855
  total sectors: 285442

  but then says:
  a:  1141768        0    ISO9660                        # (Cyl.    0 - 11417*)

So, what am I getting?  What I seem to get (tested this both on i386 1.4.2 and
Alpha -current) is 4 copies of each 2048-block.  I am totally unable to
explain this.  I can see that what's happening must be some confusion where
each of the 512-blocks in a 2048-block comes back as all 2048 bytes of data,
but isn't that impossible?