我无法访问笔记本电脑上通过 USB 连接的外部硬盘。操作系统是 ubuntu 14.04。
dmesg | tail -n 20输出如下。
[ 153.014931] sd 7:0:0:0: [sdc] Mode Sense: 00 00 00 00
[ 153.014986] sd 7:0:0:0: [sdc] Asking for cache data failed
[ 153.014995] sd 7:0:0:0: [sdc] Assuming drive cache: write through
[ 153.015387] sd 7:0:0:0: [sdc] READ CAPACITY failed
[ 153.015395] sd 7:0:0:0: [sdc]
[ 153.015400] Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK
[ 153.015403] sd 7:0:0:0: [sdc] Sense not available.
[ 153.015456] sd 7:0:0:0: [sdc] Asking for cache data failed
[ 153.015462] sd 7:0:0:0: [sdc] Assuming drive cache: write through
[ 153.015469] sd 7:0:0:0: [sdc] Attached SCSI disk
[ 153.259237] usb 4-2: new SuperSpeed USB device number 3 using xhci_hcd
[ 153.278397] usb 4-2: New USB device found, idVendor=13fd, idProduct=3940
[ 153.278406] usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 153.278411] usb 4-2: Product: Passport 0740
[ 153.278415] usb 4-2: Manufacturer: WD MY
[ 153.278419] usb 4-2: SerialNumber: 30303030303030303030303030303030
[ 153.387560] usb-storage 4-2:1.0: USB Mass Storage device detected
[ 153.387833] scsi8 : usb-storage 4-2:1.0
[ 154.389598] scsi 8:0:0:0: Direct-Access WD MY Passport 0740 0203 PQ: 0 ANSI: 6
[ 154.390220] sd 8:0:0:0: Attached scsi generic sg3 type
我该如何解决这个问题？