Subj : copy images under OpenBSD
To   : Jasen Betts
From : Lawrence Garvin
Date : Sun Dec 10 2000 02:04 am

Jasen Betts said in a message to Lawrence Garvin:

 LG> Wait... is this a BLANK CD-R????

 JB> I think it's a CDROM he wants to make a copy of.

I thought so too, but was trying to get some clarification.

I'm still not sure about the -current- contents of the CD media being read.

 JB> before it can be copied you need to know how big the original is...

And.. my previous point.. that is NOT a true statement. I have -never- seen an 
implementation where one needed to know the size of the media in order to 
perform a 'dd' copy. 'dd' should read from the input (if) device to the output 
(of) device until it runs out of data to read.

 UL>> But the CD-Rs with 700M are more expensive and if i do not know
 UL>> the size, i risk to ruin a 650M CD-R.

 LG> Uh... are you planning to write more than 650MB to the CD-R?

 JB> I guess the answer there is maybe.

Then I would think he'd need to be using a device driver written to support 
non-standard CD-R sizes, aside from the existant 'dd' issue.

 LG> Methinks there's a bug in the device driver.

 JB> That or a bug in dd.

Possibly in 'dd'.. but lest we forget.. in the realm of a single utility for a 
single process, the 'dd' utility is totally unaware of the type or metholodogy 
of its input and output sources. It is merely a stream I/O processor that moves 
bytes from the IF= device to the OF= device in block sizes specified by the 
user using the BS= parameter.

More likely that the CD driver (IF=) is failing to properly recognize the 
end-of-media condition.

Or.. that the media is entirely blank, in which case there is -no- end-of-media 
to be read.

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 * Origin: lawrence@fido.eforest.net | The Enchanted Forest (1:106/6018)

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