Filesystems and the single-user mode
Hierarchy

maddog explains the importance of single-user mode and filesystem hierarchy standards.
A friend of mine was trying to shut his system down to single-user system (SUS) mode. Although many modern-day GNU/Linux users probably do not know what SUS is, the "old people" who are familiar with Unix and earlier versions of GNU/Linux certainly are aware of it.
SUS is when most of services – such as web servers, database engines, and other "service" features – are shut down. Users (even local users) cannot log onto the system and, typically, the graphics from the X Window System are also turned off. More importantly (for my friend), all of the filesystems other than the root filesystem (represented by /) are unmounted and idle.
In this state, the systems administrator can fix many things that are wrong without completely shutting down the system and turning off the power. In this state, the admin can move things around in the filesystems or make a filesystem bigger or move it to another disk.
[...]
Buy this article as PDF
(incl. VAT)