dvd+rw-tools && pioner 111L

Он и должен писать на /dev/hdc.
А в какой момент ошибку выдаёт?

Понятно что должен, только непишет.

Ghost:10:51:46@~# /tmp/dvd+rw-tools-7.0/growisofs -Z /dev/hdc -J -R -q /mnt/tmp1/video/Films/nasa WARNING: /dev/hdc already carries isofs! About to execute 'mkisofs -J -R -q /mnt/tmp1/video/Films/nasa | builtin_dd of=/dev/hdc obs=32k seek=0' :-( unable to umount /dev/hdc: Permission denied Ghost:10:51:52@~#

В коде за это сообщение отвечает вот такой вот кусок:

set_errno(errno&FATAL_MASK);
        if (errno)
        {   if (errno==EBUSY)
                fprintf (stderr,":-( %s: unable to proceed with recording: ",
                            in_device),
#ifdef __hpux
                fprintf (stderr,"device is mounted\n"),
#else
                fprintf (stderr,"unable to unmount\n"),
#endif
                exit (FATAL_START(errno));
            else
                fprintf (stderr,":-( unable to umount %s: ",in_device);
            perror (""), exit (FATAL_START(errno));
        }


Пойду натравлю на него gdb.

growisofs не даёт писать от пользователя. Читаем руководство:
If executed under sudo(8) growisofs refuses to start. This is done  for
       the following reason. Naturally growisofs has to access the data set to
       be recorded to DVD media, either indirectly by letting mkisofs generate
       ISO9660  layout on-the-fly or directly if a pre-mastered image is to be
       recorded. Being executed under sudo(8),  growisofs  effectively  grants
       sudoers  read  access  to any file in the file system. The situation is
       intensified by the fact that growisofs parses MKISOFS environment vari-
       able  in  order  to  determine  alternative  path to mkisofs executable
       image. This means that being executed under sudo(8),  growisofs  effec-
       tively  grants  sudoers  right  to execute program of their choice with
       elevated privileges. If you for any reason still find the above accept-
       able  and  are  willing to take the consequences, then consider running
       following wrapper script under sudo(8)  in  place  for  real  growisofs
       binary.

            #!/bin/ksh
            unset SUDO_COMMAND
            export MKISOFS=/path/to/trusted/mkisofs
            exec growisofs "$@"

       But  note that the recommended alternative to the above "workaround" is
       actually to install growisofs set-root-uid, in which case it will  drop
       privileges  prior  accessing data or executing mkisofs in order to pre-
       clude unauthorized access to the data.

       If the media already carries isofs and growisofs  is  invoked  with  -Z
       option non-interactively, e.g. through cron, it shall fail with "FATAL:
       /dev/dvd already carries isofs!" Note that only ISO9660 is  recognized,
       you can perfectly zap e.g. an UDF filesystem non-interactively.

       "Overburn"  protection  in  pre-mastered  image context works only with
       plain files and ISO9660 formatted volumes. E.g. [given  that  /dev/root
       is  an ext2 formatted file system larger than 4.7GB] /dev/dvd=/dev/root
       is bound to produce corrupted recording.

       Note that DVD+RW re-formatting procedure does not substitute for blank-
       ing.  If you want to nullify the media, e.g. for privacy reasons, do it
       explicitly with ’growisofs -Z /dev/dvd=/dev/zero’.

       Playback of re-writable DVD media, both DVD+RW  and  DVD-RW,  might  be
       limited  in  legacy  DVD-ROM/-Video units. In most cases this is due to
       lower reflectivity of such media.

       Even though growisofs supports it, playback of multi-session write-once
       DVD might be limited to the first session for two reasons:


       ·      not  all DVD-ROM players are capable of multi-border DVD-R play-
              back, even less are aware of DVD+R multi-sessioning, burner unit
              therefore  might  be  the  only  one in your vicinity capable of
              accessing files written at different occasions;

       ·      OS might fail to mount multi-session DVD for various reasons;

       The above is not applicable to DVD+RW, DVD-RW Restricted  Overwrite  or
       DVD-RAM, as volumes are grown within a single session.

> Пойду натравлю на него gdb
Извращенец! Хотя занятно, позанимаюсь-ка я тоже травлей gdb на growisofs! ;-)

$ ls -l /usr/bin/growisofs 
-rwxr-xr-x 1 root root 81148 2006-11-13 13:27 /usr/bin/growisofs

$ ls -l /dev/hda
brw-rw---- 1 root cdrom 3, 0 2007-03-16 20:41 /dev/hda

$ id
uid=1000(sergey) gid=1000(sergey) groups=[SKIP],24(cdrom)

Все пишет, без прав root_a

Что-то не заметил, ничего говорящего о том, что growisofs не будет писать из-под root'а.

Самое интересное, что значение errno буквально сразу после запуска равно 6.

>в /etc/fstab в опциях указано noauto

Добавь опцию user

Натолкнулся в документации к growisofs в разделе "Does it work with my recorder unit?" на следующую фразу: " ... as well as nonplus units such as Pioneer DVR-x0[45679], LG GxA-40[248]x, Toshiba SD-R[56]112, Panasonic UJ-811, LF-D[35]..." не смотря на то, что у меня DVR-111 дело может быть в этом.

Была. уж В исходном сообщении написал, что запись производиться из-под учётной записи root, она бы погоды не сделала.

надо добавить себя в группу disk ? или какая там группа у устройства.

Блин, что же все какие умные-то, да исходное сообщение по диагонали читаете? Из под root пробовал писать, какие там ещё разрешения?