fstab and ext4 - stop constant disk access, change commit value

Ext4 does by default commit data to the disk every 5:th second sometimes resulting in writes all the time.

To change this value you add commit=seconds to the options for the relevant (root) partition in /etc/fstab.

Example (NOTE that you cannot copy paste the whole line - you must edit your own):

# / was on /dev/sdXY during installation
UUID=Your-Root-Partition-UUID /               ext4    errors=remount-ro,commit=300 0       1