Determine the File System type in Linux

blkid /dev/sda1

blkid -t TYPE=ext4

sudo parted -l

file -s /dev/sda1

tune2fs -l /dev/sda1 | grep features

df -T

mount

cat /proc/mounts

cd /proc/fs and ls

cd /sys/fs and ls

cat /etc/fstab

dumpe2fs /dev/sdb1 | head -15 -- has_journal means it is ext3.

dumpe2fs /dev/sdb1 | head -15 -- has_journal means it is ext4.

Ref : - http://unix.stackexchange.com/questions/60723/how-do-i-know-if-a-partition-is-ext2-ext3-or-ext4