On Linux-based operating system the /etc directory is used to hold global configuration files for applications and services. A good set of configurations is really important for a good working system, so being able to keep track of changes and quickly revert them, in case something go wrong, is crucial. Etckeeper helps us achieve this goal keeping configuration files under version control.
In a previous tutorial we discussed about the /etc/fstab file, and how it is used to declare the filesystems which should be mounted on boot. In the pre-Systemd era, filesystem where mounted in the order specified in the /etc/fstab file; on modern Linux distributions, instead, for a faster boot, filesystem are mounted in parallel. Systemd manages the mounting of filesystems via specifically designed units automatically generated from /etc/fstab entries. For these reasons a different strategy must be adopted to establish the dependency between two filesystems, and therefore to set their correct mount order.