Today I tried to burn some of my movies onto a DVD+R. About halfway through the process, the burn was interrupted.
OK, let me explain. The DVD-writer is at 10.23.4.1, which is my small server, I’m at 10.23.4.99, which is my laptop, and I’m accessing the server through SSH. I burn the DVD on the command line using growisofs, so if the ssh session was interrupted in any way, the burn would be interrupted. What happened today was that my terminal (mrxvt) died, so everything under it was killed (including the active ssh session). I fired up another terminal and logged in to the server, and this time I see that the disc was "incomplete" and "appendable". So I tried to resume the burn, and it succeeded!
root@darkstar:/mnt/hd# growisofs -dvd-compat -speed=8 -Z /dev/dvd=movies1.isoExecuting 'builtin_dd if=movies1.iso of=/dev/dvd obs=32k seek=0'/dev/dvd: "Current Write Speed" is 8.2x1352KBps. 
resuming track#1 from LBA#1275392 184320000/4599001088 ( 4.0%) @28.0x, remaining 1:35 RBU 0.0% UBU 0.0% 312442880/4599001088 ( 6.8%) @27.7x, remaining 1:36 RBU 0.0% UBU 0.0% 443645952/4599001088 ( 9.6%) @28.4x, remaining 1:43 RBU 0.0% UBU 0.0% 573833216/4599001088 (12.5%) @28.2x, remaining 1:38 RBU 0.0% UBU 0.0% 705789952/4599001088 (15.3%) @28.6x, remaining 1:33 RBU 0.0% UBU 0.0% 837779456/4599001088 (18.2%) @28.6x, remaining 1:34 RBU 0.0% UBU 0.0% 968523776/4599001088 (21.1%) @28.3x, remaining 1:29 RBU 0.0% UBU 0.0% 1089961984/4599001088 (23.7%) @26.3x, remaining 1:26 RBU 0.0% UBU 0.0% 1212317696/4599001088 (26.4%) @26.5x, remaining 1:26 RBU 0.0% UBU 0.0% 1340604416/4599001088 (29.1%) @27.8x, remaining 1:22 RBU 0.0% UBU 0.0% 1466695680/4599001088 (31.9%) @27.3x, remaining 1:19 RBU 0.0% UBU 0.0% 1592786944/4599001088 (34.6%) @27.3x, remaining 1:17 RBU 0.0% UBU 0.0% 1721401344/4599001088 (37.4%) @27.8x, remaining 1:13 RBU 0.0% UBU 0.0% 1849360384/4599001088 (40.2%) @27.7x, remaining 1:09 RBU 0.0% UBU 0.0% 1977647104/4599001088 (43.0%) @27.8x, remaining 1:07 RBU 0.0% UBU 0.0% 2106621952/4599001088 (45.8%) @27.9x, remaining 1:03 RBU 0.0% UBU 0.0% 2235564032/4599001088 (48.6%) @27.9x, remaining 1:00 RBU 0.0% UBU 0.0% 2357264384/4599001088 (51.3%) @26.4x, remaining 0:58 RBU 0.0% UBU 0.0% 2480078848/4599001088 (53.9%) @26.6x, remaining 0:54 RBU 0.0% UBU 0.0% 2604269568/4599001088 (56.6%) @26.9x, remaining 0:51 RBU 0.0% UBU 0.0% 2612887552/4599001088 (56.8%) @1.9x, remaining 0:53 RBU 100.0% UBU 0.0% 2631499776/4599001088 (57.2%) @4.0x, remaining 0:55 RBU 99.9% UBU 99.3% 2669051904/4599001088 (58.0%) @8.1x, remaining 0:55 RBU 100.0% UBU 99.3% 2706604032/4599001088 (58.9%) @8.1x, remaining 0:56 RBU 100.0% UBU 99.3% 2744188928/4599001088 (59.7%) @8.1x, remaining 0:56 RBU 100.0% UBU 99.3% 2781773824/4599001088 (60.5%) @8.1x, remaining 0:56 RBU 99.9% UBU 99.3% 2819358720/4599001088 (61.3%) @8.1x, remaining 0:57 RBU 99.9% UBU 99.3% 2856943616/4599001088 (62.1%) @8.1x, remaining 0:57 RBU 99.5% UBU 99.1% 2894528512/4599001088 (62.9%) @8.1x, remaining 0:57 RBU 100.0% UBU 99.3% 2932113408/4599001088 (63.8%) @8.1x, remaining 0:57 RBU 100.0% UBU 99.3% 2969698304/4599001088 (64.6%) @8.1x, remaining 0:57 RBU 100.0% UBU 99.3% 3007315968/4599001088 (65.4%) @8.1x, remaining 0:56 RBU 100.0% UBU 99.3% 3044900864/4599001088 (66.2%) @8.1x, remaining 0:56 RBU 100.0% UBU 99.3% 3082518528/4599001088 (67.0%) @8.1x, remaining 0:56 RBU 100.0% UBU 99.3% 3120136192/4599001088 (67.8%) @8.1x, remaining 0:55 RBU 100.0% UBU 99.3% 3157753856/4599001088 (68.7%) @8.1x, remaining 0:55 RBU 100.0% UBU 99.3% 3195371520/4599001088 (69.5%) @8.1x, remaining 0:54 RBU 100.0% UBU 99.3% 3233021952/4599001088 (70.3%) @8.2x, remaining 0:53 RBU 99.9% UBU 99.3% 3270639616/4599001088 (71.1%) @8.1x, remaining 0:53 RBU 100.0% UBU 99.3% 3308257280/4599001088 (71.9%) @8.1x, remaining 0:52 RBU 100.0% UBU 99.3% 3345907712/4599001088 (72.8%) @8.2x, remaining 0:51 RBU 99.9% UBU 99.3% 3383525376/4599001088 (73.6%) @8.1x, remaining 0:50 RBU 100.0% UBU 99.3% 3421175808/4599001088 (74.4%) @8.2x, remaining 0:49 RBU 99.9% UBU 99.3% 3458793472/4599001088 (75.2%) @8.1x, remaining 0:48 RBU 100.0% UBU 99.3% 3496443904/4599001088 (76.0%) @8.2x, remaining 0:47 RBU 100.0% UBU 99.3% 3534094336/4599001088 (76.8%) @8.2x, remaining 0:46 RBU 100.0% UBU 99.3% 3571744768/4599001088 (77.7%) @8.2x, remaining 0:45 RBU 100.0% UBU 99.3% 3609395200/4599001088 (78.5%) @8.2x, remaining 0:44 RBU 100.0% UBU 99.3% 3647045632/4599001088 (79.3%) @8.2x, remaining 0:42 RBU 100.0% UBU 99.3% 3684696064/4599001088 (80.1%) @8.2x, remaining 0:41 RBU 100.0% UBU 99.3% 3722379264/4599001088 (80.9%) @8.2x, remaining 0:40 RBU 99.9% UBU 99.3% 3760029696/4599001088 (81.8%) @8.2x, remaining 0:38 RBU 100.0% UBU 99.3% 3797680128/4599001088 (82.6%) @8.2x, remaining 0:37 RBU 100.0% UBU 99.3% 3835363328/4599001088 (83.4%) @8.2x, remaining 0:36 RBU 99.9% UBU 99.3% 3873013760/4599001088 (84.2%) @8.2x, remaining 0:34 RBU 100.0% UBU 99.3% 3910696960/4599001088 (85.0%) @8.2x, remaining 0:32 RBU 99.9% UBU 99.3% 3948347392/4599001088 (85.9%) @8.2x, remaining 0:31 RBU 100.0% UBU 99.3% 3986030592/4599001088 (86.7%) @8.2x, remaining 0:29 RBU 100.0% UBU 99.3% 4023713792/4599001088 (87.5%) @8.2x, remaining 0:28 RBU 99.9% UBU 99.1% 4061364224/4599001088 (88.3%) @8.2x, remaining 0:26 RBU 100.0% UBU 99.3% 4099047424/4599001088 (89.1%) @8.2x, remaining 0:24 RBU 100.0% UBU 99.1% 4136730624/4599001088 (89.9%) @8.2x, remaining 0:23 RBU 99.9% UBU 99.3% 4174413824/4599001088 (90.8%) @8.2x, remaining 0:21 RBU 100.0% UBU 99.3% 4212097024/4599001088 (91.6%) @8.2x, remaining 0:19 RBU 100.0% UBU 99.3% 4249780224/4599001088 (92.4%) @8.2x, remaining 0:17 RBU 100.0% UBU 99.3% 4287496192/4599001088 (93.2%) @8.2x, remaining 0:16 RBU 99.9% UBU 99.3% 4325179392/4599001088 (94.0%) @8.2x, remaining 0:14 RBU 99.9% UBU 99.3% 4362862592/4599001088 (94.9%) @8.2x, remaining 0:12 RBU 99.9% UBU 99.3% 4400545792/4599001088 (95.7%) @8.2x, remaining 0:10 RBU 99.9% UBU 99.3% 4438228992/4599001088 (96.5%) @8.2x, remaining 0:08 RBU 99.9% UBU 99.3% 4475912192/4599001088 (97.3%) @8.2x, remaining 0:06 RBU 100.0% UBU 99.3% 4513595392/4599001088 (98.1%) @8.2x, remaining 0:04 RBU 100.0% UBU 99.3% 4551278592/4599001088 (99.0%) @8.2x, remaining 0:02 RBU 100.0% UBU 99.3% 4588994560/4599001088 (99.8%) @8.2x, remaining 0:00 RBU 29.9% UBU 99.3%builtin_dd: 2245616*2KB out @ average 13.4x1352KBps/dev/dvd: flushing cache/dev/dvd: closing track/dev/dvd: closing discroot@darkstar:/mnt/hd# eject /dev/dvdroot@darkstar:/mnt/hd# eject -t /dev/dvdroot@darkstar:/mnt/hd# syncroot@darkstar:/mnt/hd# cmp /dev/dvd movies1.isocmp: EOF on movies1.isoroot@darkstar:/mnt/hd#
As we can see, first growisofs realizes that the disc was incomplete, so it seeked to the correct position and resumed burning (look at the speeds). It finished cleanly, and then I reloaded the disc (no need to walk over and press the eject button — I just love Linux!). Then I compared the image to the dvd itself, and they were the same. Well, except for the padding beyond the image, which is why cmp complained about "EOF on movies1.iso".
Nice. Never thought I could resume a failed DVD+R burn. I don’t know about DVD-R though, as I heard they are more fragile and more susceptible to burn errors. I myself would stay away from those, and use DVD+R and CD-R exclusively.
