Re: Problem with growisofs -- cannot write multisession DVDs without ejecting and reloading tray

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

>> xorriso

> "Chorizo"?  "Shore-Isso"?  "Zoar-Eyesoh"?

X/Open on Rock Ridge enhanced ISO 9660 = xorriso 

I'm german and pronounce it like english "ksorreeso".
But actually one has just to know how to write its name. :))


> But can it display the contents of the not-mounted filesystem without using
> DVD+RW? 

If you want it lengthy and complete:

  xorriso -indev /dev/sr0 -find / -exec lsdl --

If you know what you look for

  xorriso -indev /dev/sr0 -lsl /my/file/or/directory '/another/x*' --

Or if you like a dialog session:

  xorriso -dialog on

then put in command lines like

  -dev /dev/sr0
  -lsl / --
  -dus /my/directory --
  -tell_media_space
  -end

or manipulate the ISO for adding another session

  -rm_r /do/not/want/this/tree/any/more --
  -mv /old/path /newly/invented/path --
  -map /tree/from/disk /tree/in/iso
  -for_backup

cause writing of the new session by

  -commit

or revoke the changes by

  -rollback_end


Note that these are not options, which one can submit
in any sequence, but rather commands which get executed
in the sequence they are given. I.e. you first need
to read the metadata by -indev before you can inquire
them by -find.
Commands with a variable number of arguments get their
end marked by '--', so that more than one command can be
witten into one line. Line end is equivalent to '--',
though. You may as well end any command by '--'. Surplus
'--' get ignored. Command -list_delimiter can choose
another delimiter string instead of '--'.

man xorriso(1) has 4730 lines which hopefully explain
most of its properties. Users are advised to start
with the EXAMPLES section.


> Yeah, we have been accepting a waste of 200MB on the first session as a fact
> of life. 

The 200 MB probably are due to a decision of the drive
which believes that the first session needs to be larger
than the few KB which you did put in. (I know of a 1 GB
minimum size for DVD-R DAO. But your run was Incremental,
rather than DAO.)

If the use case needs write-once media:
DVD+R waste only 4 MB per session.


> Would the kernel developers take this particular problem more seriously if
> more people complained about it?

The place to complain would be LKML (Linux Kernel Mailing List).
Be aware that the language there can be very direct (cough)
and that nobody there waited for a userlander who cannot
fix his kernel problems by own means.
(We userlanders better solve our problems were we live.)


> > Solaris has no option to mount an older session.

> That is curious to me, since as I said, the way I proved this wasn't a
> "hardware problem" was by showing that it worked on Solaris 10.

OpenSolaris snv 134 always mounts the youngest session.
(There are traces in growisofs that Solaris once mounted
 always the first session.)
Linux (by mount -o sbsector=) and FreeBSD (by mount -s) offer an
opportunity to mount any of the sessions if you know their start
block (e.g. from xorriso command -toc). 

Solaris man mount(8) does not offer such an option.
I peeked into the OpenSolaris kernel and saw no means to send
down a start block parameter to the function which chooses
the superblock address for mounting. 


Have a nice day :)

Thomas