Our nightly backups outgrew the 500GB disks I was using so I've bought some 1TB disks, and they aren't working properly. Both the old and new disk are USB3 disks on a USB3 controller which seems to require a reboot every 50 plug/unplug cycles or so but otherwise previously worked well. The symptoms are: [ 7455.667194] sd 16:0:0:0: [sdj] Attached SCSI disk [ 7690.448638] EXT3-fs error (device sdd1): ext3_find_entry: reading directory #2 offset 0 [ 7690.448972] Buffer I/O error on device sdd1, logical block 0 [ 7690.448994] lost page write due to I/O error on sdd1 [ 7690.448999] EXT3-fs (sdd1): I/O error while writing superblock [ 7690.449056] EXT3-fs (sdd1): error: ext3_journal_start_sb: Detected aborted journal (the first message is an indication of when I plugged the disk in, the second is the start of it having errors) The disk itself seems okay and doesn't fail at a specific sector each time or anything, and I've tried another disk too. The USB3 cable is quite long, so I've replaced it with a shorter one and so far it's backed up 10GB since I started writing this email. On other tests it's written out around 200GB before failing. The possibilities I can think of are: . cable bad (it's well less than 3M) . usb disk incompatible with controller (USB3 controllers of that vintage are a bit hit and miss) . usb disk drawing too much power (shouldn't USB log an error about this? Are there tools to check?) . bad batch of drives (all pass smart tests) . something else Any thoughts? It's one of those problems that takes hours to test each troubleshooting step and meanwhile offsite backups are not getting done (20GB now and counting!) Thanks James