How to Create a New Ext4 File System in Linux?

The hard disk in a computer is formatted with specific file system so that the operating system can read and write into it. For UNIX based systems we have various type of file systems. In this article we will see how to format a new partition in hard disk with ext4 file system.

Available Filesystem types

First we see what are the different file systems available for the current operating system. The below command lists all those file systems.

$ ls -1 /sbin/mkfs*

Running the above code gives us the following result −

/sbin/mkfs
/sbin/mkfs.bfs
/sbin/mkfs.cramfs
/sbin/mkfs.ext2
/sbin/mkfs.ext3
/sbin/mkfs.ext4
/sbin/mkfs.ext4dev
/sbin/mkfs.fat
/sbin/mkfs.minix
/sbin/mkfs.msdos
/sbin/mkfs.ntfs
/sbin/mkfs.vfat

Look at the Current Partitions

Next let's look at the the current hard disk and their partitions available to the operating system. Based on this output we can decide to add a new hard disk or create a new partition in the existing desk and format it as ext4.

$ sudo fdisk -l
[sudo] password for ubuntu:

Running the above code gives us the following result −

Disk /dev/sda: 20 GiB, 21474836480 bytes, 41943040 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
Disklabel type: dos
Disk identifier: 0x06807e05

Device    Boot   Start      End       Sectors    Size    Id   Type
/dev/sda1  *      2048    33554431    33552384   16G    83   Linux
/dev/sda2       33556478  41940991    8384514     4G     5   Extended
/dev/sda5       33556480  41940991    8384512     4G     82  Linux swap / Solaris

Adding a new partition

Using the same command but choosing a different argument as shown below. We see all the available formats that the OS can support and available for formatting.

$ sudo fdisk /dev/sda
Command (m for help): l

Running the above code gives us the following result −

0    Empty               24       NEC DOS            81    Minix / old Lin    bf   Solaris
1    FAT12               27       Hidden NTFS Win    82    Linux swap / So    c1   DRDOS/sec (FAT-
2    XENIX root          39       Plan 9             83    Linux              c4   DRDOS/sec (FAT-
3    XENIX usr           3c       PartitionMagic     84    OS/2 hidden or     c6   DRDOS/sec (FAT-
4    FAT16 
Next we choose the n option to create a new partition.
Command (m for help): n
Command action
   l logical (5 or over)
   p primary partition (1-4)
First sector (39849982-41940991, default 39849982):
Using default value 39849982
Last sector, +sectors or +stze(K,M,G} (39849982-41940991, default 4
1940991):
Using default value 41940991
Now we issue the below command to make the sda5 partiton as a ext4 partition.
sudo mkfs.ext4 /dev/sda5