Enable data=writeback for root filesystem (linux)

Some people already found out the hard way that simply changing the /etc/fstab to make the root filesystem use the journal writeback modus will break the system.

The trick to enable this feature is relative simple and involves 1 additional step to editing the /etc/fstab

Lets use the below /etc/fstab snippet to illustrate the steps involved

/dev/sda5 / defaults 0 0

We change this /etc/fstab snippet to:

/dev/sda5 / data=writeback 0 0

And we execute the following command:

tune2fs -O journal_data_writeback /dev/sda5