On Monday 31 May 2004 12:56, Zainul M Charbiwala wrote:
The CD was written in 4 different sessions, with only
the last one
failing. Thus the TOC of the first three sessions should be
readable in the Lead-in of the 3rd session. But the trouble is the
driver does not detect the CD in the drive because it tries to read
the TOC from the failed lead-in of the 4th session, and the 'open'
That is what cdfs avoids. So i think that the cd is physically damaged
or ur drive and cd combo is problematic. Suggest u try cdfs on
another drive preferably LG (found samsung to be real bad).
What software did u use to record the cd?
Nero ! ( I have driver problems with my writer in Linux on my
Some more info from the web on multisession using cdrecord. Dont know
where I got the info from.
cdrecord dev=0,0 -msinfo
This means that the previous session started at sector 0 (i.e. it was
the first) and that subsequent sessions will start at sector 105248.
You can now use this information in the mkisofs command line:
# mkisofs -J -r -V Session2 -C 0,105248 -o output.iso /path/to/back/up
Alternatively, you can use the shell's command substitution functions
to use the output from cdrecord directly in your mkisofs command
# mkisofs -J -r -V Session2 -C $(cdrecord dev=0,0 -msinfo) -o
This has the effect of building a new filesystem and accounting for
the fact that this session won't start at the beginning of the CD
while generating the TOC.
Since multisession-compatible drives read the last session recorded on
the CD, any earlier sessions will be lost. Read the next section to
find out how to combine the TOC of the previous session with that of
the new one, thus keeping all the data on the CD.
Combining the TOC of an existing session with the new TOC
Computer CD-ROM drives which are multisession-compatible read the last
session written, so one of the effects of writing a new session is
losing the previous one. This isn't usually the desired effect...
There is, however, a way round it. We have to read the previous
session's TOC and incorporate it into the new TOC. That way, there
will be entries for files in the previous session (or sessions, if
there's more than one already on the CD) in the TOC of this session.
The new, combined, TOC will therefore contain entries for data in the
new session alongside entries for data in previous sessions.
We use the -M device command line option in mkisofs to achieve this,
where device follows the usual x,y notation as used by cdrecord (0,0
in the examples used here). The effect of -M is to instruct mkisofs
to open the device specified, read the TOC of the last session on the
media present in it, and incorporate this TOC into the TOC to be
generated for the new session.
The partially written media obviously has to be in the drive when
executing this command so that we can read the starting point of the
previous and of this session and the previous session's TOC.
Our full command line is now going to look like this:
# mkisofs -J -r -V Session2 -C `cdrecord dev=0,0 -msinfo` -M 0,0 -o
Special considerations for burning multisession CD-ROM's
If you want to be able to add further sessions to your CD after
burning this one, then you have to tell cdrecord to burn it in a way
which allows this. Unless otherwise instructed, cdrecord will just
write the session and fixate the CD with a normal lead-out, making it
impossible to add anything more.
This is what the -multi command line option is for.
# cdrecord dev=0,0 -v -eject speed=8 fs=16m -multi your_iso_file.iso
The CD will be cut in the usual fashion: device 0,0, verbose, eject
when done, 8x speed, 16MB FIFO. When the data has been written,
cdrecord will fixate the CD in a manner which allows a subsequent
TOC, and therefore another session, to be written.
Once you decide that the session you're about to write is going to be
the last one, you can omit the -multi option, and a final lead-out
will be written after the data, finally closing the CD.
PS : BadCopy Pro has a unique 'Mode 2' wherein it just tries to
read anything in the drive, regardless of whether there's anything
in the drive or not. I could not find this feature in any other
software. Is there any Linux CD recovery software at all ?
Zainul M Charbiwala