The Linux filesystem is responsible for storing your system data and managing them. A filesystem can be defined as the mechanism behind data storing and retrieval.
The entire Linux installation resolves around the / point. It is called the root of the file system and is essentially the starting point of your system. It contains several directories, most bearing some historical significance.
Increase the size of an ext2, ext3 or ext4 filesystem
Reduce the size of an ext2, ext3 or ext4 filesystem
Reduce the space reserved for root on an ext2, ext3 or ext4 filesystem