In the scenarios when dd fails, the amount that dd reads before failing varies from to movie dvd to movie dvd. At times dd will read 400MB before failing.
A few FWIW snippets: dvdbackup 'fixes' the dd problem xorriso doesn't 'fix' the dd problem xorriso has similar problem to dd dvdbackup 'fixes' the xorriso problem as well I haven't spent the time to let dvdbackup or xorriso complete. ===== When I insert a non-movie dvd (eg a debian install disc I burned) dmesg -w doesn't report anything. When I insert a movie dvd, dmesg -w reports: [] sr 4:0:0:0: [sr0] tag#20 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [] sr 4:0:0:0: [sr0] tag#20 Sense Key : Illegal Request [current] [] sr 4:0:0:0: [sr0] tag#20 Add. Sense: Read of scrambled sector without authentication [] sr 4:0:0:0: [sr0] tag#20 CDB: Read(10) 28 00 00 3b 23 c0 00 00 40 00 [] blk_update_request: I/O error, dev sr0, sector 15503104 [] sr 4:0:0:0: [sr0] tag#28 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [] sr 4:0:0:0: [sr0] tag#28 Sense Key : Illegal Request [current] [] sr 4:0:0:0: [sr0] tag#28 Add. Sense: Read of scrambled sector without authentication [] sr 4:0:0:0: [sr0] tag#28 CDB: Read(10) 28 00 00 3b 23 ce 00 00 02 00 [] blk_update_request: I/O error, dev sr0, sector 15503160 [] Buffer I/O error on dev sr0, logical block 1937895, async page read Is that normal? Details in the dmesg report vary from movie dvd to movie dvd, but remain the same for a given movie dvd upon subsequent cycles of eject/insert. ===== Versions: dd (coreutils) 8.26 xorriso 1.4.6 dvdbackup 0.4.2 ===== After inserting a movie dvd, dmesg -w makes no no additional reporting for: 1) dvdbackup -M then Ctrl-C nor 2) xorriso -outdev /dev/sr0 -check_media use=outdev data_to=/sdb1/movie.udf then Ctrl-C nor 3) dvdbackup -M then (Ctrl-C) then /bin/dd if=/dev/sr0 of=/sdb1/movie.iso In particular, in (3), dd finishes without causing additional dmesg reporting. Also, subsequent reissues of the dd command doesn't cause additional dmesg reporting.. FWIW, I haven't spent the time to let dvdbackup or xorriso complete. However, after inserting a movie dvd, running ... 4) /bin/dd if=/dev/sr0 of=/sdb1/movie.iso or 5) xorriso command then Ctrl-C then dd if=/dev/sr0 of=/sdb1/movie.iso ... causes the following dmesg output: [] sr 4:0:0:0: [sr0] tag#4 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [] sr 4:0:0:0: [sr0] tag#4 Sense Key : Illegal Request [current] [] sr 4:0:0:0: [sr0] tag#4 Add. Sense: Read of scrambled sector without authentication [] sr 4:0:0:0: [sr0] tag#4 CDB: Read(10) 28 00 00 00 04 b8 00 00 40 00 [] blk_update_request: I/O error, dev sr0, sector 4832 [] sr 4:0:0:0: [sr0] tag#7 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [] sr 4:0:0:0: [sr0] tag#7 Sense Key : Illegal Request [current] [] sr 4:0:0:0: [sr0] tag#7 Add. Sense: Read of scrambled sector without authentication [] sr 4:0:0:0: [sr0] tag#7 CDB: Read(10) 28 00 00 00 04 b8 00 00 02 00 [] blk_update_request: I/O error, dev sr0, sector 4832 [] Buffer I/O error on dev sr0, logical block 604, async page read In this scenario, subsequent reruns of the dd command cause dmesg to reissue the same report. Also, following this scenario, dmesg -w does not issue additional reporting when running ... dvdbackup -M, then Ctrl-C, /bin/dd if=/dev/sr0 of=/sdb1/movie.iso ===== xorriso behaves similarly to dd. it succeeds only if dvdbackup -M is run first. Here is the output when running it without dvdbackup -M ... MD> xorriso -outdev /dev/sr0 -check_media use=outdev data_to=/sdb1/movie.udf xorriso 1.4.6 : RockRidge filesystem manipulator, libburnia project. xorriso : NOTE : Disc status unsuitable for writing Drive current: -outdev '/dev/sr0' Media current: DVD-ROM Media status : is written , is closed Media summary: 1 session, 3871183 data blocks, 7561m data, 0 free xorriso : UPDATE : 32 blocks read in 3 seconds , 0.0xD libburn : SORRY : SCSI error on read_10(1216,32): See MMC specs: Sense Key 5 "Illegal request", ASC 6F ASCQ 03. libburn : SORRY : SCSI error on read_10(1248,32): See MMC specs: Sense Key 5 "Illegal request", ASC 6F ASCQ 03.
