Re: Multisession DVD creation problem.

[Joerg Schilling <Joerg Schilling fokus fraunhofer de>]

Thomas Schmitt <scdbackup gmx net> wrote:

> ------------------------------------------------------------------------
> Quite technical discussion:
>
> Joerg Schilling wrote:
> > DVD+R does not have the concept of "sessions" this is why I asked.
>
> This is not true. They can have multiple tracks. As soon as a track gets
> closed it becomes a session.  (See MMC-5, 4.3.6.2 "Recording on DVD+R",
> especially 4.3.6.2.1.3 "Sessions".)
>
> With write-once use cases i'm nearly only using BD-R media meanwhile.
> But i found a 10 year old backup DVD+R with 50 sessions (153 max):
>
>   Media current: DVD+R
>   Media product: RITEK/F16/49 , Ritek Corp
>   Media status : is written , is appendable
>   Media blocks : 2282864 readable , 10192 writable , 2295104 overall
>   TOC layout   : Idx ,  sbsector ,       Size , Volume Id
>   ISO session  :   1 ,         0 ,    739194s , UPDATE_HOME_2008_06_22_191945
>   ISO session  :   2 ,    741392 ,     20333s , UPDATE_HOME_2008_06_25_190436
>   ISO session  :   3 ,    763936 ,     19565s , UPDATE_HOME_2008_06_29_001832
>   ISO session  :   4 ,    785712 ,     30291s , UPDATE_HOME_2008_06_30_220849
>   ... more sessions ...
>   ISO session  :  47 ,   2142608 ,     18932s , UPDATE_HOME_2008_11_19_180117
>   ISO session  :  48 ,   2163744 ,     35100s , UPDATE_HOME_2008_11_25_102435
>   ISO session  :  49 ,   2201056 ,     46953s , UPDATE_HOME_2008_11_30_201431
>   ISO session  :  50 ,   2250208 ,     32503s , UPDATE_HOME_2008_12_04_190853
>   Media summary: 50 sessions, 2182512 data blocks, 4263m data, 19.9m free
>   Media nwa    : 2284912s

Note that cdrecord lists this as "tracks" and it would only be useful if all
drives will return the expected sector number for the read session offset 
"command". Could you confirm this?



> > cdrecord -v -media-info
>
> From our merry bug hunt with the bad power supply on forums.ubuntuusers.de
> in 2015 i still have a binary of cdrecord-3.02a05.
> So with my old backup DVD+R of 2008:
>
>   $ ./cdrecord-fubude-3 -v dev=/dev/sr4 -media-info

Please never use that unsupported dev=/dev/sr4 as this may force libscg to fall 
back to a worse kernel interface for SCSI generic transport than what libscg 
uses by default with either no dev= parameter or with the official 
SCSI address method from the SCSI standard.

>   Cdrecord-ProDVD-ProBD-Clone 3.02a05-fubude-3 (x86_64-unknown-linux-gnu) Copyright (C) 1995-2015 Joerg 
> Schilling
>   TOC Type: 1 = CD-ROM

This is a "patch" that includes a workaround for a Linux kernel driver bug that 
was reported in January 2016 and fixed in the original source a few days later 
(as usual with the cdrtools project).

Since then, the option "scgopts=ignore-resid" tells cdrecord to ignore the DMA 
residual count that is assumed to be always incorrectly reported from the 
driver. This usually happens with USB connected drives.

It is better to use recent versions of cdrtools....


>   ... various complaints about not being superuser ...

So the binary was not correctly installed.

> growisofs is indeed unmaintained. But libburn and libisoburn learned a lot
> from it. So its spirit lives on.

growisofs is a C++ program that has been written as if it was assembler.
Aditionally, there is a lot of incorrect code inside that makes is a miracle 
why it could work with some drives (it e.g. sends incorrect SCSI "mode select" 
commands to the drive.

Jörg

-- 
 EMail:joerg schily net                    (home) Jörg Schilling D-13353 Berlin
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