Jaunty Jackalope (RESOLVED)

[Rashkae]

NoOp wrote:

> 
> Yep. I was thinking about the CD issue (must have been a full moon out
> last night).
> 
> 

And for my part, I apologize for my first comment on this thread.  While
I certainly have never hesitated to jump into a cozy flameware, I mean
no disrespect to you NoOp

For anyone who's interested, I offer some further thoughts on cd burn
verification.

In theory, CD's, and especially dvd's.. already have tons of error
correction and checksumming built in.  I have probably too much faith in
this built in error checking, and almost never bother verifying
checksums of burned ISO's or files.   Either the drive is able to read
the data from the disc, or it reports I/O errors.  Therefore, when I
want to verify a burn (and indeed, all burns should be checked, in some
form or other,) I simply do ddrescue /dev/dvd /dev/null and keep an eye
on the output.

If ddrescue reports any errors or 'rescued' sectors, then the disc is a
coaster.  It's also useful to keep an eye on the kb/s as the disc is
read.  This should start relatively small at the start of the disc, and
become much faster by the time you reach the outer edge.  (on my
hardware, I go from 9000 KB/s at start to 17000 KB/s at end of DVD)  If
you notice dips in the reading speed, that is an indication that the
drive had trouble reading some areas of the disc, even if it was able to
recover every byte with no error.