All USB users face or will face the mounting problem  or formating problem. Don’t worry users . Here I have some tips for you.

The first thing you need to do.
1. Insert your USB drive into your system.

2. Open the terminal. (CTRL + ALT + T)

And type  ->  df -h
df -h For finding out where it is mounted
3.then  unmount this USB drive using the following command.

$ sudo umount /dev/sdc1
4.Now use one of the following commands as per file system you want. To format a USB drive most users prefer VFAT and NTFS file systems because they can be easily used on Windows operating system.

Format with vFat FileSystem

$ sudo mkfs.vfat /dev/sdc1
Format with NTFS FileSystem

$ sudo mkfs.ntfs /dev/sdc1

Format with EXT4 FileSystem

$ sudo mkfs.ext4 /dev/sdc1

So you are done with the formatting of pen-drive.The main use that I have by formatting the pen drive from the terminal is that we can format almost any type of pen-drive .