How to Create a New Ext4 File System (Partition) in Linux?

The ext4 or fourth extended filesystem is a widely-used journaling file system for Linux. It was designed as a progressive revision of the ext3 file system and overcomes a number of limitations in ext3.

Creating a New Partition in Linux

List the partitions using the fdisk -l or parted -l commands to identify the hard drive you want to partition.

# fdisk -l 
OR
# parted -l

Looking at the output in the screenshot above, we have two hard disks added on the test system and we will partition disk /dev/sdb.

Now use parted command to start creating the partition on the selected storage device.

# parted /dev/sdb

Now give the new disk a label using the mklabel command.

(parted) mklabel msdos

Then create a partition using the mkpart command, give it additional parameters like “primary” or “logical” depending on the partition type that you wish to create. Then select ext4 as the file system type, set the start and end to establish the size of the partition:

(parted) mkpart                                                            
Partition type? primary/extended? primary 
File system type? [ext2]? ext4 
Start? 1 
End? 20190

To print the partition table on the device /dev/sdb or detailed information about the new partition, run the print command.

(parted) print

Now exit the program using the quit command.

Formatting New Ext4 Partition

Next, you need to properly format the new partition with the ext4 file system type using the mkfs.ext4 or mke4fs command as follows.

# mkfs.ext4 /dev/sdb1
OR
# mke4fs -t ext4 /dev/sdb1

Then label the partition using the e4label command as follows. 

# e4label /dev/sdb1 disk2-part1
OR
# e2abel /dev/sdb1 disk2-part1

Mounting New Ext4 Partition in File System

Next, create a mount point and mount the newly created ext4 partition file system.

# mkdir /mnt/disk2-part1
# mount /dev/sdb1 //mnt/disk2-part1

Now using the df command, you can list all file systems on your system together with their sizes in a human-readable format (-h), and their mount points and file system types (-T):

# df -hT

Lastly, add the following entry in your /etc/fstab to enable persistent mounting of the file system, even after a reboot.

/dev/sdb1   /mnt/disk2-part1  ext4   defaults    0   0