XenServer output of '# dmesg | tail -n 40' for USB2 port

# dmesg | tail -n 40
[194476.659311] ata9.00: irq_stat 0x00060002, device error via D2H FIS
[194476.659318] ata9: SError: { 10B8B }
[194476.659324] ata9.00: failed command: READ DMA
[194476.659333] ata9.00: cmd c8/00:08:00:00:00/00:00:00:00:00/e0 tag 0 dma 4096 in
[194476.659334]          res 51/04:08:00:00:00/00:00:00:00:00/e0 Emask 0x1 (device error)
[194476.659347] ata9.00: status: { DRDY ERR }
[194476.659352] ata9.00: error: { ABRT }
[194476.666435] ata9.00: configured for UDMA/33
[194476.666448] sd 8:0:0:0: [sdf] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[194476.666451] sd 8:0:0:0: [sdf] Sense Key : Aborted Command [current] [descriptor]
[194476.666456] Descriptor sense data with sense descriptors (in hex):
[194476.666457]         72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00
[194476.666464]         00 00 00 00
[194476.666468] sd 8:0:0:0: [sdf] Add. Sense: No additional sense information
[194476.666471] sd 8:0:0:0: [sdf] CDB: Read(10): 28 00 00 00 00 00 00 00 08 00
[194476.666478] end_request: I/O error, dev sdf, sector 0
[194476.666490] Buffer I/O error on device sdf, logical block 0
[194476.666506] ata9: EH complete
[195036.498428] usb 1-1: USB disconnect, address 2
[195036.691895] hub 1-0:1.0: over-current change on port 7
[195036.801873] hub 1-0:1.0: over-current change on port 8
[195520.014914] usb 1-3: new high speed USB device using ehci_hcd and address 3
[195520.166694] usb 1-3: configuration #1 chosen from 1 choice
[195520.166915] scsi11 : SCSI emulation for USB Mass Storage devices
[195520.167022] usb-storage: device found at 3
[195520.167024] usb-storage: waiting for device to settle before scanning
[195527.858153] scsi 11:0:0:0: Direct-Access     ST4000DM 000-1CD168       CC43 PQ: 0 ANSI: 5
[195527.858342] sd 11:0:0:0: Attached scsi generic sg3 type 0
[195527.877744] usb-storage: device scan complete
[195527.880373] sd 11:0:0:0: [sdc] 976754646 4096-byte logical blocks: (4.00 TB/3.63 TiB)
[195527.882619] sd 11:0:0:0: [sdc] Write Protect is off
[195527.882622] sd 11:0:0:0: [sdc] Mode Sense: 23 00 00 00
[195527.882624] sd 11:0:0:0: [sdc] Assuming drive cache: write through
[195527.883522] sd 11:0:0:0: [sdc] 976754646 4096-byte logical blocks: (4.00 TB/3.63 TiB)
[195527.885782] sd 11:0:0:0: [sdc] Assuming drive cache: write through
[195527.885795] sdc: detected capacity change from 0 to 4000787030016
[195527.885801]  sdc: sdc1 sdc2
[195528.047132] sd 11:0:0:0: [sdc] 976754646 4096-byte logical blocks: (4.00 TB/3.63 TiB)
[195528.049627] sd 11:0:0:0: [sdc] Assuming drive cache: write through
[195528.049639] sd 11:0:0:0: [sdc] Attached SCSI disk