use of journaling in ext3 and ext4

vikilinux · 04-03-2014, 02:17 AM

Hai friends

As I heard that ext2 filesystem doesn't having journaling feature while ext3 and ext4 having the same.

So what is the use of journaling,is this making big difference or what???

colucix · 04-03-2014, 02:38 AM

Basically a journaling filesystem helps in preserving the integrity of data, especially in case of a sudden power off during writing operations. Here is a good and concise definition.

Just take in mind that ext3 and ext4 filesystem reserve part of the disk/partition to write journaling information. To retrieve info about the size and location of the journal on a partition (as root):

Code:

dumpe2fs /dev/sda1 | grep ^Journal

Kowalski · 04-03-2014, 05:15 AM

Wikipedia?

Two more resources to complement the previous answer are here and here

Also: journaling is a feature that can be disabled

This other thread on LQ has some insight as well.