Uncommon users of Ubuntu OS, when connecting USB with NTFS file system, can observe the error: "Error mounting / dev / sdb1" or "Failed to mount '/ dev / sdb1': Input / output error".
The cad file in the NTFS system has a corresponding entry in the MFT (Master File Table). NTFS reserves the first 16 MFT records for storing special information. The first entry describes directly the MFT itself, followed by a description of the backup MFT mirror record. If the first MFT record is corrupted, NTFS will read the second entry to find the MFT mirror, the first record of which is identical to the first entry in the MFT. The location of the MFT and MFT mirror is spelled out in the boot sector of the disk.
Source: NTFS.com
After incorrect extraction of the USB disk, a power failure, and for other reasons, the MFT may be damaged and the first MFT mirror entry will not match the first MFT record.
The utility ntfsfix will help to solve the problem :
sudo ntfsfix /dev/sdb1
* / dev / sdb1 - you need to specify the section that is mentioned in the error text.
If the ntfsfix utility is not available, you can install it with the ntfs-3g package :
sudo apt-get install ntfs-3g
After using ntfsfix, the initialization data on the device will be restored as well as access to the USB device.
参考自：http://www.rebelcode.ru/linux/error-mounting-devsdb1-v-ubuntu/