Identify Linux File System Type

5 Methods to Identify Your Linux File System Type (Ext2 or Ext3 or Ext4)

by RAMESH NATARAJAN on APRIL 18, 2011

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Question: How do I identify my file system type? I like to upgrade my current file system to the latest ext4. Before that I would like to know what my current file system type is for various mount points I have on my UNIX system.

Answer: Use any one of the five methods mentioned below to identify your file system type.

Method 1: Use df -T Command

The -T option in the df command displays the file system type. 

# df -T | awk '{print $1,$2,$NF}' | grep "^/dev"/dev/sda1 ext2 //dev/sdb1 ext3 /home/dev/sdc1 ext3 /u01

Method 2: Use Mount Command

Use the mount command as shown below.

# mount | grep "^/dev"/dev/sda1 on / type ext2 (rw)/dev/sdb1 on /home type ext3 (rw)/dev/sdc1 on /u01 type ext3 (rw)

As shown in the above example:

• /dev/sda1 is ext2 file system type. (mounted as /)
• /dev/sdb1 is ext3 file system type. (mounted as /home)
• /dev/sdc1 is ext3 file system type. (mounted as /u01)

Method 3: Use file Command

As root, use the file command as shown below. You need to pass the individual device name to the file command.

# file -sL /dev/sda1/dev/sda1: Linux rev 1.0 ext2 filesystem data (mounted or unclean) (large files)# file -sL /dev/sdb1/dev/sda1: Linux rev 1.0 ext3 filesystem data (needs journal recovery)(large files)# file -sL /dev/sdc1/dev/sda1: Linux rev 1.0 ext3 filesystem data (needs journal recovery)(large files)

Note: You should execute the file command as root user. If you execute as non-root user, you’ll still get some output. But, that will not display the file system type as shown below.

$ file -sL /dev/sda1/dev/sda1: writable, no read permission

Method 4: View the /etc/fstab file

If a particular mount point is configured to be mounted automatically during system startup, you can identify its file system type by looking at the /etc/fstab file.

As shown in the example below, / is ext2, /home is ext3, and /u01 is ext3.

# cat /etc/fstabLABEL=/r       /        ext2    defaults    1 1LABEL=/home    /home    ext3    defaults    0 0LABEL=/u01     /u01     ext3    defaults    0 0

Method 5: Use fsck Command

Execute the fsck command as shown below. This will display the file system type of a given device.

# fsck -N /dev/sda1fsck 1.39 (29-May-2006)[/sbin/fsck.ext2 (1) -- /] fsck.ext2 /dev/sda1# fsck -N /dev/sdb1fsck 1.39 (29-May-2006)[/sbin/fsck.ext3 (1) -- /home] fsck.ext3 /dev/sdb1# fsck -N /dev/sdc1fsck 1.39 (29-May-2006)[/sbin/fsck.ext3 (1) -- /u01] fsck.ext3 /dev/sdc1

If you don’t have the root access, but would like to identify your file system type, use /sbin/fsck -N as shown above.