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Re: Some suggestions for changes to w.d.o/CD/faq entries


Andrei Popescu <andreimpopescu@gmail.com> wrote:
> [1] I have no idea what checkreading is supposed to mean

With the optical media types DVD-RAM and BD-RE, the drives verify the
readability of the written data before they get overwritten in the drive
buffer. If not properly readable, blocks from the spare area are mapped
into the address space as replacement of the bad blocks.

What sounds like a good thing, works very poorly in practice.
The affected media get written with half or third of their nominal speed.
If problems arised on my drives, then the media staid unusable despite all
the internal effort of the drive.
Further one cannot trust that readability check. What was written without
error might still throw read errors only a few minutes later.

So it is desirable to write "2x" BD-RE with 9 MB/s rather than with 3 MB/s
and to verify the image checksum by a separate read run.

Have a nice day :)


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