I'm running Debian/Squeeze and have just switched to using an LG BH12LS35 Blu-ray writer for backups - to replace a DVD writer and DVD-RAM discs. However it doesn't seem to work the way I thought it should.

The DVD-RAM discs I'd been using were UDF-formatted (mkudffs /dev/sr0) and would hold about 4.3G. I would simply copy files onto them then unmount and eject the disc.

With the Blu-ray BD-RE discs, df /dev/sr0 only reports about 1G of space after formatting, and the file copy seems to concur. It reports being out of space after about 1G of copying.

If I do a dvd+rw-format /dev/sr0 (with or without the -force=full option), the dvd+rw-format program reports 24.4G media but afterward I'm still left with only 1G being reported.

I also tried to use growisfs -Z /dev/sr0 -R -J <files to backup>. It appeared to work, but I can't access files past the first 1G on the disc.

Any ideas on what is happening?

Interesting. Last night's backup worked. I've verified that the files are readable on the backup disc and df /media/dvd shows the correct space. Must have been a problem with the other backup disc.