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Re: Blu-Ray disk capacities really?



Hi,

> Supposedly, I can write 25025314816 bytes to a single sided BD-R,
>  unformatted:           12219392*2048=25025314816

Yup. If it is not formatted.


>  32h(3000):             11826176*2048=24220008448
> That 24220008448 number is awfully close to 98% of
> 24711716864, so is that the real capacity of a Blu-Ray
> for storing data, or is the default write technique
> k3b is using not the one I want?

growisofs is quite eager to format them. Maybe this option would
prevent it:
  -use-the-force-luke=spare=none


> What the heck do those different format capacities mean?

You may use BD-R unformatted. Then they perform no checkreading
during write and do not replace blocks which fail that check.
Checkreading reduces write speed to 50 % or even 30 %.
Block replacement does not show convincing improvements for me.

So my programs xorriso and cdrskin do not format BD-R by default.

If formatting is desired, it has to be applied before the first
write operation on the medium.

The list you see, shows an overview of possible formatted sizes.
The moderate proposal
    32h(3000):             11826176*2048=24220008448
gives 768 MiB of spare blocks for replacement.
The extreme proposal would reserve nearly 10 GB spare.

dvd+rw-mediainfo is showing quite directly the results of SCSI/MMC
commands which our burn programs use to learn about the loaded
medium and its state. (There are many possibilities.)


> I'm trying to figure out how to stash data files on my new
> Blu-Ray writer under linux,

My program xorriso is specialy designed for data archiving by
multiple sessions. You may do more than one smaller experiment
with the same BD-R until you have filled it up.

Be invited to try it and to ask me if you need advise.


> and I'm using up media faster than I'm learning anything :-).

Better get a BD-RE for practicing. :))


Have a nice day :)

Thomas


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