Ubuntu 10.10 writes corrupted Blu-Ray BD-R
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
cdrkit (Ubuntu) |
Expired
|
Undecided
|
Unassigned |
Bug Description
Binary package hint: genisoimage
BACKGROUND, NEED
When writing a blu-ray disc, you need to assemble an image that is then written to the disc
Ubuntu 10.10 can recognize and write to blu-ray, but data is corrupted along the way
to do blu-ray portable with large files, you need an iso9660 image with udf
to be windows friendly, you need joliet
to be mac/linux friendly, you need rock ridge
this is all accomplished while writing the iso image
it is not practically feasible to do this command line, because long filenames need to be resolved for joliet/rock ridge
therefore, a frontend such as k3b is used
k3b needs to do two things: create the iso image and write that image to the blu-ray media
- there seems to be no way to successfully write to dual-layer media
- otherwise writing to single layer media concludes with an error message but does produce a somewhat readable disc
more serious issue: the data in the created iso image is corrupt, which can be verified by using md5sum
SYMPTOM
1. pick you favorite folder with a size of 10 GiB or so
2. make that folder your current directory and generate an md5um file using for example:
find . -name md5sum.txt -prune -o -type f -exec md5sum -b {} ";" >md5sum.txt
3. create some project in k3b, instruct to create iso image only
4. mount that iso image and run the md5sums using something like
sudo mount -o loop -t udf myiso.iso myemptyfolder
5. cd into that folder and verify your md5 hashes
md5sum -c md5sum.txt
BUG: checksums are corrupt
CAUSE
the iso is generated in either of three ways
1. using the 10.10 genisoimage/wodim packages (from Ubuntu 10.10)
foxyboy@xpc21:~$ wodim -version
Cdrecord-
Wodim 1.1.10
Copyright (C) 2006 Cdrkit suite contributors
Based on works from Joerg Schilling, Copyright (C) 1995-2006, J. Schilling
foxyboy@xpc21:~$ genisoimage -version
genisoimage 1.1.10 (Linux)
foxyboy@xpc21:~$
ISSUE: Wodim does not support blu-ray
2. Using an older version of cdrtools, for example (removed in Hardy due to licensing issues https:/
foxyboy@
mkisofs 2.01.01a33 (i686-pc-linux-gnu) Copyright (C) 1993-1997 Eric Youngdale (C) 1997-2007 J�rg Schilling
ISSUE: this crashes spectacularly at command line for any data beyond a handful lines of text under 8.3 filename
3. Using cdrtools 3.00 (https:/
ISSUE: does something but produces corrupt file data as reported by md5sum under SYMPTOM.
Note: no matter if you use cdrtools or growisofs, in the end they both rely on mkisofs which is the root cause of the problem
get-around: on mac snow leopard, this seems to work using Finder
You unfortunately do not describe your problem in a way that would allow to understand the reason.
genisoimage is based on a more than 6 year old cdrtools version with additional
bugs (specific to the fork) added. You cannot expect such an old and unmaintained
software to support large files correctly.
The original software "cdrtools" however has been constantly enhanced during the past 6 years.
If you use the original cdrtools (and avoid to use the symlinks that just point to the defective
fork), you get software that supports large files and Blu-Ray correctly.
The support for large files in mkisofs has been added in Autumn 2007. Unfortunately, k3b
only recently started to call the real mkisofs with the -sort option that allows to contol the
location of file related data on the medium. This caused a -sort related problem with
files > 4 GB to be unveiled last week. There is a preliminary fix for this problem:
ftp://ftp. berlios. de/pub/ cdrecord/ alpha/cdrtools- 3.01a01- pre.tar. bz2
A final 3.01a01 version will be published this week.