Re: [Bug-xorriso] How to write 27G file to BD-R D

[Thomas Schmitt]

Hi,

> # growisofs --dvd-compat --allow-limited-size -Z /dev/dvdrw \
>     /mnt/big/check_size.lz
> It took "real 44m1.384s" and produced a UDF file system.
> ...
> # xorriso -for_backup -outdev /dev/dvdrw -fs 64m \
>           -map /mnt/big/check_size.lz /check_size.lz \
>           -commit_eject all
> produced an iso9660 file system and took "real 18m47.341s".

The time difference is probably due to the habit of growisofs to format
all BD media and then not to suppress Defect Management, which checkreads
during write and relocates addresses of poorly readable blocks to the
Spare Area. Even with flawless media this slows burning by a factor 2 or 3.

You can avoid this on BD-R media by growisofs option
  -use-the-force-luke=spare=none
On BD-RE media it cannot be avoided, because they must be formatted.
xorriso offers command
  -stream_recording "on"
to disable Defect Management on formatted media.

I wonder why mkisofs/genisoimage underneath growisofs produced an UDF
without you giving option -udf or -video. (The result is most probably
an ISO 9660 / UDF hybrid.)


> address@hidden:~# diff /mnt/test/check_size.lz /mnt/big/check_size.lz
> address@hidden:~#

Did you try whether your earlier BD-R can be read by lz4c if you pipe in
the stream from /dev/dvdrw by help of "cat" ?


> > I did not spend money yet on buying 50 GB media.

> If you give me an address, I will try to figure out how to get amazon.de
> to send you a few.

Thank you for the offer. But it is not lack of money or opportunity which
kept me from buying BD-R DL. Users report that they work with libburn just
like single layer BD-R. I myself have no use case which would justify the
higher price compared with two single layer BD-R.

The current problem with growisofs is its lack of an upstream maintainer.
It has a few flaws, which could be quite easily repaired. But even most
of the distro packagers seem to have lost interest:
  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=699186
  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=794868


Have a nice day :)

Thomas