Linux: Methods to Identify Your Linux File System Type
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/fstab LABEL=/r / ext2 defaults 1 1 LABEL=/home /home ext3 defaults 0 0 LABEL=/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/sda1 fsck 1.39 (29-May-2006) [/sbin/fsck.ext2 (1) -- /] fsck.ext2 /dev/sda1 # fsck -N /dev/sdb1 fsck 1.39 (29-May-2006) [/sbin/fsck.ext3 (1) -- /home] fsck.ext3 /dev/sdb1 # fsck -N /dev/sdc1 fsck 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.
By: Ramesh Natarajan
