I having a similar problem.

Getting the response as shown in the attached image when execute following command:

ls /dev/ | grep sd

Note: 'sdb' is shown when I connect the hard disk.

prostocks@prostocks:~$ ls /dev/ | grep sd
prostocks@prostocks:~$ dmesg | tail
[ 3309.121192] Read(10): 28 00 00 00 00 01 00 00 01 00
[ 3309.231156] sd 8:0:0:0: [sdb] Unhandled sense code
[ 3309.231160] sd 8:0:0:0: [sdb]  
[ 3309.231161] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 3309.231163] sd 8:0:0:0: [sdb]  
[ 3309.231164] Sense Key : Medium Error [current] 
[ 3309.231166] sd 8:0:0:0: [sdb]  
[ 3309.231167] Add. Sense: Unrecovered read error
[ 3309.231169] sd 8:0:0:0: [sdb] CDB: 
[ 3309.231170] Read(10): 28 00 00 00 00 02 00 00 06 00
  • looks like its drawing too much power, can you supply extra power to the disk?
    – j0h
    Commented Nov 14, 2019 at 6:45
  • How could it be possible? Sorry I didn't understand. Commented Nov 14, 2019 at 6:47

1 Answer 1


your disk is failing to read for some reason, you must find out why to figure out what to do next. This line tells you that: Add. Sense: Unrecovered read error

install SMART disk analysis tools using: sudo apt-get install smartmontools

with your disk plugged in, run: smartctl -a /dev/sdb you should get more info about why your disk isn't mounting. The problem may be related to high current draw, in which case you might look at the power supply for the device. Alternatively, your disk may have internal errors such as failing sectors, or bad blocks that are preventing it from mounting.

Another command you could try to get more info from is: dd if=/dev/sdb of=/dev/null && sudo dmesg this will tell you if the driver is ok, and possibly the specific types od io errors you may be getting.

post output from these listed commands.

  • Here is the output of commands - prostocks@prostocks:~$ smartctl -a /dev/sdb smartctl 6.2 2013-07-26 r3841 [x86_64-linux-3.13.0-24-generic] (local build) Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org /dev/sdb: Unknown USB bridge [0x0bc2:0xab24 (0x100)] Please specify device type with the -d option. Use smartctl -h to get a usage summary prostocks@prostocks:~$ sudo dd if=/dev/sdb of=/dev/null && sudo dmesg dd: error reading ‘/dev/sdb’: Input/output error 0+0 records in 0+0 records out 0 bytes (0 B) copied, 0.392352 s, 0.0 kB/s Commented Nov 18, 2019 at 5:55

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