[Gllug] Slurp an entire tape to file with dd

[Robert Newson]

Tom Schutzer-Weissmann wrote:

> Hello,
> 
> We're having a *lot* of fun trying to restore some backup tapes made
> with Veritas 8.6. The rant potential is considerable...
> 
> I would like to transfer the entire 40GB of tape to a file, and so tried
> this in Knoppix:
> 
> 	dd if=/dev/nst0 of=/mnt/myusbdisk bs=128k
> 
> But dd will stop (without any error) and although repeating the command
> will read another chunk of unpredictable length, I'm worried bits are
> getting missed out and simply splicing the chunks together won't work.
> 
> Since dd doesn't report any I/O error I'm assuming its coming across
> EOF. 
> 
> Is there any way I can say "do your absolute damnedness to read 327680
> blocks of 128k from this device"?

$ info dd
...
`ibs=BYTES'
      Read BYTES bytes at a time.
...
`count=BLOCKS'
      Copy BLOCKS `ibs'-byte blocks from the input file, instead of
      everything until the end of the file.

any use?

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