How to Determine the File System Type in Linux (Ext2, Ext3 or Ext4)?

Linux supports various file system types like Ext2, Ext3, and Ext4, each with different features such as journaling and file size limits. Determining the file system type of your storage devices is essential for system administration and troubleshooting.

Using lsblk Command

The lsblk command displays all attached devices along with their file system types and partitions ?

$ lsblk -f

Running the above command gives us the following result −

NAME   FSTYPE LABEL UUID                                 MOUNTPOINT
sr0    
sda    
??sda2 
??sda5 swap         02a54ace-c5c2-41cf-a679-acd9b460ee79 [SWAP]
??sda1 ext4         ae7c051f-451b-45ad-80a3-347c70a9de5e /

Using file Command

The file command provides detailed information about the disk file system type ?

$ sudo file -sL /dev/sda1

Running the above command gives us the following result −

/dev/sda1: Linux rev 1.0 ext4 filesystem data, UUID=ae7c051f-451b-45ad-80a3-347c70a9de5e (needs journal recovery) (extents) (large files) (huge files)

Using fsck Command

Though fsck is primarily used to repair file systems, it also reveals file system types ?

$ fsck -N /dev/sda1

Running the above command gives us the following result −

fsck from util-linux 2.27.1
[/sbin/fsck.ext4 (1) -- /] fsck.ext4 /dev/sda1

Checking /etc/fstab File

The /etc/fstab file contains mount points and file system configuration details. Use the cat command to view its contents ?

$ cat /etc/fstab

Running the above command gives us the following result −

# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
# / was on /dev/sda1 during installation
UUID=ae7c051f-451b-45ad-80a3-347c70a9de5e / ext4 errors=remount-ro 0 1
# swap was on /dev/sda5 during installation
UUID=02a54ace-c5c2-41cf-a679-acd9b460ee79 none swap sw 0 0
/dev/fd0 /media/floppy0 auto rw,user,noauto,exec,utf8 0 0

Using df Command

The df command with -Th options provides detailed file system information including type, usage, and mount points ?

$ df -Th

Running the above command gives us the following result −

Filesystem Type      Size  Used Avail Use% Mounted on
udev       devtmpfs  1.9G     0  1.9G   0% /dev
tmpfs      tmpfs     393M   12M  382M   3% /run
/dev/sda1  ext4       19G  4.8G   13G  28% /
tmpfs      tmpfs     2.0G  420K  2.0G   1% /dev/shm
tmpfs      tmpfs     5.0M  4.0K  5.0M   1% /run/lock
tmpfs      tmpfs     2.0G     0  2.0G   0% /sys/fs/cgroup
tmpfs      tmpfs     393M   80K  393M   1% /run/user/1000

Conclusion

These commands provide different levels of detail about file system types in Linux. Use lsblk -f for a quick overview, df -Th for usage statistics, and file command for detailed file system information.