cdrecord dummy mode doingactual writes?

carcamal · 09-09-2015, 02:50 AM

Hi!
Yesterday i found a session written on a DVD after using "cdrecord -dummy". i thought I had interchanged the disc with a previous one (I was getting many write errors even at 1x, that's why I starrted using dummy).

Today I have had the same issue. After "cdrecord -dummy dev=1,0,0 speed=1 myiso.img", cdrecord exited with error before writing 10 Mb and a disk with "blank" first track and "full" second track is created:

Mounted media class: DVD
Mounted media type: DVD-R sequential record
Disk Is not erasable
data type: standard
disk status: incomplete/appendable
session status: incomplete/appendable
BG format status: none
first track: 1
number of sessions: 1
first track in last sess: 1
last track in last sess: 2
Disk Is unrestricted
Disk type: DVD, HD-DVD or BD

Track Sess Type Start Addr End Addr Size
==============================================
1 1 Blank 0 2292287 2292288
2 1 Data 2292304 2298495 6192

Last session start address: 2292304
Last session leadout start address: 2298496
Next writable address: 2297904
Remaining writable size: 6192

Does anyone know of similar behaviours on cdrecord? I put the "-dummy" option before the "dev" option. Should I put it after it to avoid being ignored?

(N.B. cdrecord versions:
Cdrecord-ProDVD-ProBD-Clone 2.01.01a72 (i686-pc-cygwin)
Cdrecord-ProDVD-ProBD-Clone 3.01a31 (i686-pc-cygwin)
Yes, they are windows ports, but I guess linux users will have better answers for these).

astrogeek · 09-09-2015, 07:49 PM

From man cdrecord...

Code:

-dummy  The -dummy option modifies the  current  write  strategy. The 
        CD/DVD/BluRay-recorder will go through  all  steps  of the recording
        process, but the laser is turned off during this procedure.
        It is recommended to run several tests before actually writing to a 
        Compact Disk or Digital  Versatile Disk, if the timing and load response
        of the current system is not yet known.

        The -dummy option does not work with all media and write
        modes.  DVD+ media and BluRay media does not support dummy writes and most
        CD-recorders do not support dummy writes in raw mode.

Quote:

Originally Posted by carcamal

(N.B. cdrecord versions:
Cdrecord-ProDVD-ProBD-Clone 2.01.01a72 (i686-pc-cygwin)
Cdrecord-ProDVD-ProBD-Clone 3.01a31 (i686-pc-cygwin)
Yes, they are windows ports, but I guess linux users will have better answers for these).

Not sure how valid that assumption may be... it assumes a LOT about the underlying system and says nothing about the port itself!

carcamal · 09-10-2015, 10:32 AM

Thanks for you response. So that's the answer to this mistery. I just wonder why cdrecord does not issue a warning if real writes are going to be used.
I'll keep continuing with my current practice, making images from windows (where I have spare space) and burning from linux (from where cdrecord seems to work).