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The wheel group on *nix computers typically refers to the group with some sort of root-like access. I've heard that on some *nixes it's the group of users with the right to run su, but on Linux that seems to be anyone (although you need the root password, naturally). On Linux distributions I've used it seems to be the group that by default has the right to use sudo; there's an entry in sudoers for them:

%wheel ALL=(ALL) ALL

But that's all tangential; my actual question is: Why is this group called wheel? I've heard miscellaneous explanations for it before, but don't know if any of them are correct. Does anyone know the actual history of the term?

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    I've wondered about this on and off for a long time too. I see some new and not new ideas on where it may have come from. I have read about about TENEX before but that doesn't tell me who came up with the name on that project and why they picked it. So far, I don't see any verifiable references yet and, although it's old, the posting from usenet in 1987 doesn't really qualify as being verified so right now it's still just a bunch of fellow geeks proposing where they believe it came from. One theory I have and it's completely unverifiable but I am wondering if it was a developers last name?
    – jetole
    Feb 25, 2016 at 16:38
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    How is it different from the admin group, I wonder?
    – Noldorin
    Apr 4, 2016 at 20:40

8 Answers 8

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The Jargon File has an answer which seems to agree with JanC.

wheel: n. [from slang ‘big wheel’ for a powerful person] A person who has an active wheel bit...The traditional name of security group zero in BSD (to which the major system-internal users like root belong) is ‘wheel’...

A wheel bit is also helpfully defined:

A privilege bit that allows the possessor to perform some restricted operation on a timesharing system, such as read or write any file on the system regardless of protections, change or look at any address in the running monitor, crash or reload the system, and kill or create jobs and user accounts. The term was invented on the TENEX operating system, and carried over to TOPS-20, XEROX-IFS, and others. The state of being in a privileged logon is sometimes called wheel mode. This term entered the Unix culture from TWENEX in the mid-1980s and has been gaining popularity there (esp. at university sites).

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    This theory is backed up by this Usenet posting from Oct 5, 1987: [JARGON part 2 of 2 ](groups.google.com/group/comp.doc/browse_thread/thread/…)
    – Stefan Lasiewski
    Aug 27, 2010 at 15:45
  • 66
    Big Wheel, Big Cheese, Big Shot (etc) were all slang for an important person in the early and mid 20th century. Some of them are still popular today, others aren't. Big Wheel was an allusion to the wheels on carriages of previous centuries, where more important people would have carriages with larger wheels.
    – Chris S
    Apr 24, 2011 at 3:44
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As others have said, it comes from the term "Big Wheel". I think many of us are not familiar with this term because, according to at least one site, it became a popular expression after World War Two:

Big wheel is another way to describe an important person. A big wheel may be head of a company, a political leader, a famous doctor. They are big wheels because they are powerful. What they do affects many persons. Big wheels give the orders. Other people carry them out. As in many machines, a big wheel makes the little wheels turn.

Big wheel became a popular expression after World War Two. It probably comes from an expression used for many years by people who fix the mechanical parts of cars and trucks. They said a person "rolled a big wheel" if he was important and had influence.

For those like me who were born in the 1980s, we may find the following a closer cultural reference for a Big Wheel:

i got root!

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It comes to us from BSD. This is verifiable. But where did it begin?

Here is a un-verified, but maybe verifiable explanation- BSD got it from the TOPS-20 O/S.

http://lists.freebsd.org/pipermail/freebsd-chat/2003-December/001725.html

enter image description here

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    Frankly this story seems more plausible to me than the "big wheel" theory. If I had to guess, "big wheel" might have been slang that was used by some of the early UNIX crowd, but probably as a consequence of the wheel group, not the cause thereof. But who knows?
    – frabjous
    Aug 25, 2010 at 20:57
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    Eh, the "big wheel theory" says that it originates in the TENEX OS, which was the predecessor of TOPS-20, so the "big wheel theory" actually includes this "BSD theory" (TENEX -> TOPS-20 -> UNIX).
    – JanC
    Aug 26, 2010 at 11:01
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    I'm sure people have asked this question before. If the "Wheel in the sky" theory was true, there would be some discussion of this in the Usenet archives from 1981-1990. But there is zero discussion of this theory.
    – Stefan Lasiewski
    Aug 27, 2010 at 15:38
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    Good point, but the Usenet archives for that era are not complete.
    – kmarsh
    Oct 29, 2013 at 19:26
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    Lol I'd never heard of this hypothesis but I always sing that song in my head when I'm editing group permissions that touch "wheel".
    – Californian
    Feb 3, 2021 at 20:29
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Wikipedia knows it?

The term is derived from the slang term big wheel, referring to a person with great power or influence

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    I've heard that before, although I've personally never heard anyone use the slang "big wheel". I've also heard that it refers to a "wheel of trust", but that seems equally dubious, and I've seen this mailing list question that pretty much concludes nobody knows for sure
    – Michael Mrozek
    Aug 25, 2010 at 19:34
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    Find out which unix system first used it... and then try to find the people working there at that time and ask them.
    – xenoterracide
    Aug 25, 2010 at 19:51
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    I've always tought it is as in steering wheel - people who have access to steering wheel and therefore can influence the direction of system.
    – Maciej Piechotka
    Aug 25, 2010 at 20:55
  • It seems like the original source of Wikipedia is FOLDOC.
    – JanC
    Aug 26, 2010 at 7:13
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    All these people saying that they've never personally heard the phrase "big wheel" are ignoring the fact that UNIX was created over 40 years ago by people who were already in their 20's or 30's at that time. It was a very common turn of phrase in their lifetimes.
    – Mark Reed
    Dec 11, 2013 at 20:24
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Before TENEX was TOPS-10 and the Monitor (running on the PDP-10 (https://en.wikipedia.org/wiki/PDP-10) and PDP-6 (https://en.wikipedia.org/wiki/PDP-6) respectively). When it was needed to run diagnostics while timesharing was still up, the user of the diagnostic would execute R WHEEL to gain super-user privileges. The WHEEL program was hardcoded to only allow the user logged in as [6,10] to be treated like OPER[1,2].

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On a Penny-farthing bicycle the Speed,Direction,Break almost everything of the vehicle are in the "BIG WHEEL".

so is the root and group.

parts root

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If you're in the wheel group you can take the wheel -- think nautical.

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"Wheel" can be short for wheelhouse, on a boat. If people are in your wheelhouse, it means they are permitted to use the wheel and they are good at it.

wheelhouse (Oxford)

1.

a small cabin with walls and a roof on a ship where the person controlling the direction in which the ship moves stands at the wheel

  1. (North American English)

a person's area of expert knowledge or experience

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