smartctl 6.2 2013-07-26 r3841 [x86_64-linux-3.16.0-30-generic] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org

/dev/sdb: Unknown USB bridge [0x0951:0x1607 (0x100)]
Please specify device type with the -d option.

Use smartctl -h to get a usage summary