Re: Problem mounting encrypted blu-ray disc or image
Hi,
B.M. wrote:
> Do I understand correctly, you say that this Pioneer drive doesn't work well
> with Verbatim BD-RE, i.e. their rewriteable BDs.
Yes. The problem is with the high reading speed of the drive and with
a physical flaw of Verbatim BD-RE (CMCMAG/CN2/0).
The flaw is that there are letters engraved in the transparent area around
the inner hole, which reach to the thickened ring around the hole.
This ring is obviously essential for physical stability and the letters
weaken it enough so that 10 to 20 full read runs on my Pioneer BDR-209
are enough to produce a radial crack at the hole. This crack grows towards
the rim in a few more full speed reads. As soon as the dye is reached, the
medium is unreadable.
Writing is no problem, because it happens at most at 2.0x speed.
Older Verbatim BD-RE (VERBAT/IM0/0) are no problem. But one cannot buy
them any more.
Reading the new Verbatim BD-RE media is no problem on Optiarc BD RW BD-5300S,
LG BD-RE BH16NS40, and ASUS BW-16D1HT. And of course not with the old LG
drives like BD-RE GGW-H20L which read (and write) BD-RE at 2.3x speed.
> Since I only use BD-R, it
> doesn't matter for me and my use case, but thank you nevertheless.
I tested about 50 reads with RITEK/BR3/0 and Verbatim CMCMAG/BA5/0
BD-R media. No problems. (And no engraved letters to see around the
inner hole.)
The media which you inspected by dvd+rw-medianinfo are CMCMAG/BA5
(dunno what dvd+rw-medianinfo did to the "/0" part of the name).
I am still curious whether the decryption problems are caused by
not closing the /dev/mapper device.
Have a nice day :)
Thomas
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