[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Could BD-RE disc come back to un-formatted state?

Hi Thomas,

Many thanks for your reply. The use case is that BD-RE discs need recycling to be reused again.  Currently I use dd to nullify the first 64KB to quickly clean the udf filesystem built on the BD-RE disc. But this state is different with the original blank state.  So the state switch of BD-RE disc is:
blank -> formatted -> filesystem -> formatted

In the "blank" and "formatted" states the disc actually cannot be used by users directly.  The hardware media states of "formatted" and "filestystem" are the same "complete".  I'd like to unify the "blank" and  "formatted" status to one state and make it different with the "filesystem" state.

Since it cannot be deformatted back to blank state regularly, I have to use "lsblk -o FSTYPE" to classify the "formatted" and "filesystem" states. Do you have any suggestion on this?
Your burner which could deformat BD-RE disc is really funny :-)

------------------ Original ------------------
Date:  Wed, Jan 3, 2018 04:52 PM
To:  "feng.wang"<feng.wang@aaadisc.com>;
Subject:  Re: Could BD-RE disc come back to un-formatted state?

> After being formatted, the BD-RE disc is changed to "complete" from "blank"
> status. Could we change the status back to "blank"?

Not regularly. The SCSI/MMC command set for optical media offers no
opportunity to deformat a BD-RE medium. One may only change the size of the
Spare Area.

Said this, i have an old BD burner which can do the trick by accident:
"Optiarc", model "BD RW BD-5300S", firmware "1.04".
If i insert and remove a CD-R medium then it afterwards deformats any BD-RE
medium i give to it and refuses to write them. A power-off-on cycle brings
it back to normal operation.
The affected media have to be formatted again before they can be written.

> According to the
> thread https://lists.debian.org/cdwrite/2010/02/msg00014.html, the
> "dvd+rw-format -blank" command is useless to change the status back to
> "blank". 

Indeed. The "-blank" option only applies to DVD-RW media. Those can be
de-formatted from overwritable state to sequential "blank" state (or
erased from sequential states "appendable" or "closed" to "blank").

My program xorriso extends the model of "blank", "appendable", and "closed"
to ISO 9660 sessions on overwritable media like BD-RE. Valid ISO 9660
filesystems do not get overwritten by xorriso unless they get devalidated
by a xorriso "-blank" command.
But that is only a content-orient classification. The hardware state of
such media stays "complete" and no writing can be done before the medium
gets formatted to that state.

What is your use case for which you need to de-format the BD-RE medium ?
Why would a formatted BD-RE not work for this use case ?

Have a nice day :)


Reply to: