Bon ... c'est un peu ce que je craignais..
Voici le retour de ta dernière demande :
olivier@olivier-X200MA:~$ dmesg -lerr
[ 1.172924] Couldn't get size: 0x800000000000000e
[33584.111496] scsi 2:0:0:1: Wrong diagnostic page; asked for 1 got 8
[33584.111508] scsi 2:0:0:1: Failed to get diagnostic page 0x1
[33584.111515] scsi 2:0:0:1: Failed to bind enclosure -19
[33584.119001] sd 2:0:0:0: [sdb] No Caching mode page found
[33584.119010] sd 2:0:0:0: [sdb] Assuming drive cache: write through
[33632.298531] print_req_error: critical medium error, dev sdb, sector 6759176
[33635.146702] print_req_error: critical medium error, dev sdb, sector 6760968
[33638.228933] print_req_error: critical medium error, dev sdb, sector 6762760
[33642.130029] print_req_error: critical medium error, dev sdb, sector 6766600
[33645.478940] print_req_error: critical medium error, dev sdb, sector 6768392
[33648.352851] print_req_error: critical medium error, dev sdb, sector 6768560
[33648.352879] Buffer I/O error on dev sdb1, logical block 845814, async page read
[33651.700945] print_req_error: critical medium error, dev sdb, sector 6773872
[33655.403807] print_req_error: critical medium error, dev sdb, sector 6790240
[33658.346591] print_req_error: critical medium error, dev sdb, sector 6775664
[33661.335376] print_req_error: critical medium error, dev sdb, sector 6777464
[33664.314302] print_req_error: critical medium error, dev sdb, sector 6779248
[33667.673546] print_req_error: critical medium error, dev sdb, sector 6783072
[33670.491742] print_req_error: critical medium error, dev sdb, sector 6783096
[33670.491770] Buffer I/O error on dev sdb1, logical block 847631, async page read
[33673.804870] print_req_error: critical medium error, dev sdb, sector 6784872
[33677.278439] print_req_error: critical medium error, dev sdb, sector 6786664
[33680.383131] print_req_error: critical medium error, dev sdb, sector 6788456
[33683.765314] print_req_error: critical medium error, dev sdb, sector 6792016
[33687.380024] print_req_error: critical medium error, dev sdb, sector 6793808
[33690.957426] print_req_error: critical medium error, dev sdb, sector 6795584
[33718.019739] print_req_error: critical medium error, dev sdb, sector 6734136
[33720.710342] print_req_error: critical medium error, dev sdb, sector 6734136
[33720.710371] Buffer I/O error on dev sdb1, logical block 841511, async page read
[33749.240667] print_req_error: critical medium error, dev sdb, sector 6735920
[33749.240684] Buffer I/O error on dev sdb1, logical block 841734, async page read
[33752.751503] print_req_error: critical medium error, dev sdb, sector 6737704
[33752.751527] Buffer I/O error on dev sdb1, logical block 841957, async page read
[33789.154993] print_req_error: critical medium error, dev sdb, sector 6739496
[33789.155017] Buffer I/O error on dev sdb1, logical block 842181, async page read
[33792.468115] print_req_error: critical medium error, dev sdb, sector 6741280
[33792.468138] Buffer I/O error on dev sdb1, logical block 842404, async page read
[33795.158566] print_req_error: critical medium error, dev sdb, sector 6741280
[33795.158590] Buffer I/O error on dev sdb1, logical block 842404, async page read
[33798.459105] print_req_error: critical medium error, dev sdb, sector 6743064
[33798.459124] Buffer I/O error on dev sdb1, logical block 842627, async page read
[33801.944482] print_req_error: critical medium error, dev sdb, sector 6744848
[33801.944498] Buffer I/O error on dev sdb1, logical block 842850, async page read
[33805.291048] print_req_error: critical medium error, dev sdb, sector 6746632
[33805.291059] Buffer I/O error on dev sdb1, logical block 843073, async page read
[33807.982805] print_req_error: critical medium error, dev sdb, sector 6746632
[33807.982824] Buffer I/O error on dev sdb1, logical block 843073, async page read
[33824.625852] print_req_error: critical medium error, dev sdb, sector 6710424
[33824.625875] Buffer I/O error on dev sdb1, logical block 838547, async page read
[33828.491198] print_req_error: critical medium error, dev sdb, sector 6724960
[33828.491223] Buffer I/O error on dev sdb1, logical block 840364, async page read
[33831.629756] print_req_error: critical medium error, dev sdb, sector 6728528
[33831.629763] Buffer I/O error on dev sdb1, logical block 840810, async page read
[33837.392658] print_req_error: critical medium error, dev sdb, sector 6770344
[33837.392666] Buffer I/O error on dev sdb1, logical block 846037, async page read
[33840.522056] print_req_error: critical medium error, dev sdb, sector 6772136
[33840.522085] Buffer I/O error on dev sdb1, logical block 846261, async page read
[33843.213389] print_req_error: critical medium error, dev sdb, sector 6772136
[33843.213412] Buffer I/O error on dev sdb1, logical block 846261, async page read
[33846.074873] print_req_error: critical medium error, dev sdb, sector 6777488
[33846.074896] Buffer I/O error on dev sdb1, logical block 846930, async page read
[33848.948942] print_req_error: critical medium error, dev sdb, sector 6784880
[33848.948956] Buffer I/O error on dev sdb1, logical block 847854, async page read
[33857.496245] print_req_error: critical medium error, dev sdb, sector 6792024
[33857.496268] Buffer I/O error on dev sdb1, logical block 848747, async page read
[33861.038047] print_req_error: critical medium error, dev sdb, sector 6806560
[33861.038069] Buffer I/O error on dev sdb1, logical block 850564, async page read
olivier@olivier-X200MA:~$
Donc j'ai débranché le DD comme indiqué, et j'attedns celui que j'ai commandé pour en faire une copie.
Par contre ça ne m'explique pas monpb ou quand je clique sur le lanceur d'une partititon ou d'un périphérique externe dans le lanceur Unity ce n'est pas nautilus qui se lance mais l'analyseur d'application des disques ... je pense qu'il faut que j'ouvre une autre discussion sur le forum ?
En tout cas merci pour tes réponses.