A file system is the method of storing the data in an organized manner on the disk. It is also used to refer to a partition or disk that is used to store the files or the type of the file system. Every partition on the disk except MBR and Extended partition should be assigned with some file system in order to make them store data. File system is applied on the partition by formatting it with a particular type of file system.
Linux supports numerous file systems, but common choices for the system disk on a block device include the ext* family (ext2, ext3 and ext4), XFS, JFS, ReiserFS and btrfs etc..
Ext file system is the widely used file system in Linux,whereas vfat is the file system to maintain a common storage between Linux and Windows.
How to check file system type :
$ df -T displays file system, type, block size,free, used and mount on etc..
In the output, you can see file system type.
About file systems
ext2: Second Extended file system
It was introduced in 1993. It doesn’t have feature. Maximum file size can be 16 GB to 2 TB.Maximum ext2 file system can be from 2TB to 32 TB. Can not convert ext file system to ext2.
ext3: Third extended file system
It was introduced in 2001. It supports journaling feature. Maximum file size can be 16 GB to 2 TB and maximum ext3 file system size can be from 2 TB to 32 TB. You can convert an ext2 file system to ext3 file system directly.
ext4: Fourth extended file system
It was introduced in 2008. It supports journaling feature. Maximum file size can be from 16 GB to 16 TB and maximum ext4 file system size is 1 EB (Exabyte). All previous ext file systems can easily be converted into ext4 file system.
1 EB = 1024 PB (Petabytes)
1 PB = 1024 TB (Terabytes)