After I posted some time ago in these groups about the potential to
create an EFS image on DVD media, I did some experiments in this
direction recently:

Pioneer DVD-303S (1.10 and 2.00 firmware revision) fails because data
cannot be read correctly from DVD media in 512 Bytes/sector mode.

Toshiba SD-1401 (1007 and 1010 firmware revision) fail because data
cannot be read at all from DVD media when requesting 512Bytes/sector.

Fortunately these problems can easily be investigated by reading from
the vol device file with dd.

hinv excerpt:
Integral SCSI controller 0: Version WD33C93B, revision D
Disk drive: unit 1 on SCSI controller 0
CDROM: unit 3 on SCSI controller 0
Tape drive: unit 4 on SCSI controller 0: DAT
CDROM: unit 6 on SCSI controller 0

Pioneer DVD-303S (2.00 firmware, but I think 1.10 was exactly the
same, I tried that some time ago):

# dd if=/dev/rdsk/dks0d6vol of=/var/tmp/dvd_image.303s.512 bs=512 \
160+0 records in
160+0 records out
# dd if=/dev/rdsk/dks0d6vol of=/var/tmp/dvd_image.303s.2048 \
bs=2048 count=40
40+0 records in
40+0 records out
# cmp dvd_image.303s.2048 dvd_image.303s.512
dvd_image.303s.2048 dvd_image.303s.512 differ: char 33281, line 2

the difference does appear to result from an off-by-one error in the
Pioneer Firmware: where dd bs=2048 will read a (virtual) sequence of
512 Byte sectors I call 1234567..., dd bs=512 will rather read
1123456... . That the error manifests itself at byte 33281 is because
the DVD I used in this example has an all zero bytes first sector of
32k size.

This does of course also hint at a possible "dirty" hack to prepare

Toshiba SD-1401 (1007 and 1010 firmware):

# dd if=/dev/rdsk/dks0d3vol of=/var/tmp/dvd_image.1401.2048 bs=2048 \
40+0 records in
40+0 records out
# dd if=/dev/rdsk/dks0d3vol of=/var/tmp/dvd_image.1401.512 bs=512 \
Read error: I/O error
0+0 records in
0+0 records out
# cmp dvd_image.1401.2048 dvd_image.303s.2048

The SD-1401 behaves nicely in 2048 Bytes/sector mode, but doesn't
support reading DVDs at 512 Bytes/sector.

To find out wether correctly mastered EFS-DVDs are possible at all, I
wanted to ask that someone who does have a DVD-ROM not listed above,
especially one of the Toshiba drives SGI sells, please try to put a
DVD in your drive and try the two or three commands listed above (dd
bs=512, dd bs=2048, cmp img1 img2). At my department we only have
CD-ROM drives installed with the SGIs because DVD-ROM makes little
sense when all installation media is CD and everything else takes
place over the network, but I really hate all the media changing
involved in some cases.

Thank you for your time,
Thomas Jahns
"Computers are good at following instructions,
but not at reading your mind."
D. E. Knuth, The TeXbook, Addison-Wesley 1984, 1986, 1996, p. 9