I ran your suggested command but had a couple error messages:
gnubahn@libreT400s:~$ dvdbackup -i /dev/sr0 --mirror
*** Zero check failed in ifo_read.c:576
for vmgi_mat->zero_6 =
0x0000001100000000000000000000000000000000000000000000000000000000
*** Zero check failed in ifo_read.c:576
for vmgi_mat->zero_6 =
0x0000001100000000000000000000000000000000000000000000000000000000
libdvdread: Attempting to retrieve all CSS keys
libdvdread: This can take a _long_ time, please be patient
libdvdread: Get key for /VIDEO_TS/VIDEO_TS.VOB at 0x000003a0
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_01_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_01_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_02_0.VOB at 0x0039e0c8
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_02_1.VOB at 0x003a379a
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_03_0.VOB at 0x003b871a
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_03_1.VOB at 0x003b8767
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_04_0.VOB at 0x003d7b14
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_04_1.VOB at 0x003d7b61
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_05_0.VOB at 0x003dd729
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_05_1.VOB at 0x003dd776
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_06_0.VOB at 0x003e5e62
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_06_1.VOB at 0x003e5eaf
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_07_1.VOB at 0x003ec6ef
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_08_1.VOB at 0x003ec74b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_09_1.VOB at 0x003ec7a7
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_10_1.VOB at 0x003ec80d
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_11_1.VOB at 0x003f38b6
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_12_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_12_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_13_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_13_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_14_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_14_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_15_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_15_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_16_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_16_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_17_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_17_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_18_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_18_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_19_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_19_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_20_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_20_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_21_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_21_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_22_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_22_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_23_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_23_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_24_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_24_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_25_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_25_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_26_0.VOB at 0x00008ee3
libdvdread: Elapsed time 0
libdvdread: Get key for /VIDEO_TS/VTS_26_1.VOB at 0x0001881b
libdvdread: Elapsed time 0
libdvdread: Found 26 VTS's
libdvdread: Elapsed time 0
Error reading VTS_01_1.VOB at block 14053
padding 283 blocks
Error reading VTS_01_1.VOB at block 17477
padding 443 blocks
