Disk /dev/sdb: 15.5 GB, 15547170816 bytes
64 heads, 32 sectors/track, 14826 cylinders, total 30365568 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x6f20736b

This doesn't look like a partition table
Probably you selected the wrong device.

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   ?   778135908  1919645538   570754815+  72  Unknown
/dev/sdb2   ?   168689522  2104717761   968014120   65  Novell Netware 386
/dev/sdb3   ?  1869881465  3805909656   968014096   79  Unknown
/dev/sdb4   ?  2885681152  2885736650       27749+   d  Unknown

Partition table entries are not in disk order