The kernel messages below happened the first time I plugged in a Seagate Backup Plus drive. These messages are not problems with the drive, they indicate a buggy-as-fuck kernel module called 'uas'. Blacklisting the module solves the problem and makes the drive behave normally. sd 6:0:0:4: [sdg] Result: hostbyte=0x01 driverbyte=0x00 sd 6:0:0:4: [sdg] Sense not available. sd 6:0:0:4: [sdg] READ CAPACITY failed sd 6:0:0:4: [sdg] Result: hostbyte=0x01 driverbyte=0x00 sd 6:0:0:4: [sdg] Sense not available. sd 6:0:0:4: [sdg] Write Protect is off sd 6:0:0:2: [sde] READ CAPACITY(16) failed sd 6:0:0:2: [sde] Result: hostbyte=0x01 driverbyte=0x00 sd 6:0:0:2: [sde] Sense not available. sd 6:0:0:2: [sde] READ CAPACITY failed sd 6:0:0:2: [sde] Result: hostbyte=0x01 driverbyte=0x00 sd 6:0:0:2: [sde] Sense not available. sd 6:0:0:2: [sde] Write Protect is off sd 6:0:0:6: [sdi] Attached SCSI disk sd 6:0:0:2: [sde] Attached SCSI disk sd 6:0:0:5: [sdh] Attached SCSI disk sd 6:0:0:4: [sdg] Attached SCSI disk sd 6:0:0:7: [sdj] Attached SCSI disk sd 6:0:0:1: [sdd] Attached SCSI disk sd 6:0:0:3: [sdf] Attached SCSI disk usb 1-2: reset high-speed USB device number 4 using ehci_hcd scsi7 : uas scsi 7:0:0:0: Direct-Access Seagate Backup+ Desk 050B PQ: 0 ANSI: 6 usb 1-2: USB disconnect, device number 4 sd 7:0:0:0: uas_eh_abort_handler tag 1 sd 7:0:0:0: uas_eh_abort_handler tag 0 sd 7:0:0:0: uas_eh_device_reset_handler tag 1 sd 7:0:0:0: uas_eh_target_reset_handler tag 1 sd 7:0:0:0: uas_eh_bus_reset_handler tag 0 sd 7:0:0:0: sense urb submission failure sd 7:0:0:0: uas_eh_abort_handler tag 0 sd 7:0:0:0: uas_eh_device_reset_handler tag 0 sd 7:0:0:0: uas_eh_target_reset_handler tag 0 sd 7:0:0:0: uas_eh_bus_reset_handler tag 0 sd 7:0:0:0: Device offlined - not ready after error recovery sd 7:0:0:0: Device offlined - not ready after error recovery sd 7:0:0:0: [sdc] READ CAPACITY(16) failed [...] scsi 7:0:0:1: sense urb submission failure scsi 7:0:0:1: sense urb submission failure scsi 7:0:0:1: sense urb submission failure scsi 7:0:0:1: sense urb submission failure [...] (this message repeats indefinitely until reboot)