What is "Root"?

By: cogDis, exwintech, Merlin Whitewolf, Algernon, abmman, davecs and vampirefo

Adapted from the forum thread "What is 'root'?" originally posted on: September 21, 2006, 10:43:00 PM at:
http://www.pclinuxos.com/forum/index.php?topic=10838.0

CogDis:

Here are a couple of excerpts from a previous discussion on the forum:

One of the things I have found in helping new Linux users understand the Linux way of doing things is that the concept of "root" can be a bit perplexing because of the inconsistent way it is used in the Linux lexicon. In much the same way a new computer user might confuse the concept of gigabytes of RAM with gigabytes of hard disk space, so too can newer Linux users be confused with the various connotations of root. I hope this may shed some light for someone.

  1. First of all there is "/" (pronounced root), the top most level of the root file system (as in root directory or folder). I find it ironic that "/" is used to describe the topmost level of the Linux file system when most of us probably would intuit just the opposite.....but I digress. You might think of "/" as the container for the entire root file system.
  2. The root file system. Often represented as "/" but really encompassing all of the files and folders that make up the Linux operating system.
  3. The root partition. The physical partition or drive that the root file system lives on. Also frequently referred to as "/".
  4. /root. This is not the root partition or root file system, but the home folder of the root user.
  5. root. Most frequently used to denote the user "root". Or more specifically, the name of the login account of the the administrative user that has full file system access privileges. Also known as superuser.
  6. As root, gain root, root access, etc. That is, perform some action with the administrative privileges of the root user.

You see, "root" has various connotations dependent upon the context in which it is used. It is no wonder that it is hard for many of us to grasp at first.

We won't even get into root-window, rootkit, get rooted, root portal, chroot and many other similarly phrased terms. Yikes!

Mwananchi:

It seems odd, that the root partition (hda1, hdb1, etc.) is stuck in the midst of the the file system under /mnt, because then where do all the folders and everything above root reside?

...everything above root? root is like GOD in your system, there is no "above root", everything is and must be under HIM. The whole universe is under "/". The universe is the "/", going above this is like going over the boundary of the universe, or cruising past the speed of light! What are you going to see? It just doesn't make sense.

HE has his own chilling place at '/root', where he puts his personal stuff and where his desktop is. It's locked because he is just personal.

You live in HIS universe and you have your own place to grow up in called "home directory", you live in '/home/you'.

He occasionally allows an extension to his universe from others, i.e. USB devices, hard drives, CD-ROMS, floppy drives, under '/mnt', but this isn't a requirement, HE just likes them there since HE can remember where they are all the time.

HE occasionally allows HIS children to fiddle around in places they shouldn't be by giving them temporary access to HIS powers by requiring them to provide a root access password.

HE is a very forgetful GOD so he keeps most of his physical assets in '/dev', a folder where ironically His universe is attached. (/dev/hdaX ).

He keeps most of his likes and dislikes about how HE runs his universe in '/etc'. He provided a nice place where his children and anyone who cares to know may find out what he is up to in '/proc'. Want to know what he is smoking? Well, hang around there, and if you pray hard enough, you might find out.

What of the lost+found place? ...well, He generally puts things there that He doesn't know/remember where they are supposed to be. It's locked because you aren't supposed to "see" his mistakes.

Exwintech:

In some locations, where the English spoken is not of the exceptionally well-mannered American type, the Linux Name of the Ultimate Administrator (other than Tex or Linus, natch) is a reference to the 'human procreative act' - I hope that's a sufficiently polite way to put it... It is most awkward to have to attempt to explain to those of the female gender, in these Regions of non-American (Australian) English, that they must 'su to root', to do 'Admin Tasks', as they think of it in Other Systems.

The term 'su' can sound the same when spoken, as the diminutive form of the name 'Susan', as in 'Sue'. So when used in the context meaning 'Change to Admin Mode', the connotations can be misleading, especially to ladies not at all familiar with Linux, who assume 'root' to mean something with which a plant gains nutrients from the soil, or the above slang or dialectic reference.

Perhaps some of the Forum Members from non-English-speaking regions could tell us what 'Linux Admin Mode'' is in other languages, and at least those who prefer to - when speaking to those, of course, not only ladies, as yet unfamiliar with Linux, could choose and use another word for it. Ahem...

Ahh, well, off now, to find my tongue-from-cheek remover....

Merlin Whitewolf:

Just one question for now - What arcane artifacts of electronic power does 'He' put in "/var"?

Algernon:

Let's call it "runtime information"... the stuff that gets dynamically generated when applications run.

There are however exceptions, since a *lot* of very different things go in '/var'.

Examples: '/var/log' is the repository of all logs (mostly generated by services or the kernel itself); '/var/run' is where daemons put runtime info such as their PID so other programs may detect their existence; '/var/spool' stores the job queue for all daemons which need one (cron, at, cups, mail...); '/var/lock' contains the lock files used to detect whether another process - or another instance of the same process - are using a non-shareable resource; '/var/cache' provides a good place to cache stuff for programs that need it (apt/synaptic, samba,...).

Other directories, like '/var/ftp' or '/var/www' can be used (though not necessarily) as homeland for very specific servers, such as FTP servers or Apache servers. In the latter case, the directory '/srv/www' is as far as I know frequently used to store websites. And then there are even more things in '/var'...

You see, it's kinda hard to give a general definition.

Abmman:

Well, root does not have any ambiguous meaning in Danish, but if you abbreviate Linux Admin Mode to LAM, it means either lame (in all senses of the word) or lamb. Much more funny is MUG (Microsoft User Group), which in Danish means "mold".

Davecs:

In English, MUG, as well as a large square cup, also means Face (mug-shot, ugly mug, etc) or Victim of a Scam or Robbery. (He is the mug. he was mugged). It is also general slang for fool.

Exwintech:

Root isn't the Ultimate Power in Linux, if the said Linux is running KDE. Root can be overridden at will/random - by Konqueror... Well documented by me, in the Sandbox...

Vampirefo:

The ultimate power is the person sitting in the chair typing. We control the PC not root. Root, plainly and simply, is the administrator.

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