I have tried to create a logical partition via Fdisk for a flash drive. The problem is that I choose the option -n to create a partition, of course , and fdisk gives me only two options "extended and primary". However, I want an option for logical partitions. Moreover, in a topic in the forum, a guy is able to choose logical partition option instead of extended.
The topic's link: http://ubuntuforums.org/showthread.php?t=1659376