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What's in a name - Ed's journal
What's in a name

Naming computers is one of these intricacies of Systems Administration.
It's not _quite_ as easy as it seems.

And it's one of these long running disputes.

I've seen:

ux-gl-02 (unix, graphics lab, number 2)
teg8843 (turbine engineering asset number 8843)
SURUG10001 (Server Unix, Rugby zone 1, number 0001)

Names are intrinsically related to domain. In microsoft terms that's an "NT Domain" and it's a region of shared accounting and resources.
In Unix/DNS terms, 'alstom.com' is domain (so a computer within the alstom.com domain would be phoenix.alstom.com).

The DNS/Domain structure is hierarchical. You can have each domain as a subset of another.
In general terms, '.com' is a domain, so in theory you could have 'www.com' - denoting host 'www' in the domain '.com'.

The problem is this:
Any rigid method for naming computers is essentially meaningless.
The number of times i've mentioned 'SNRUG40012' and i've had a blank look and 'which one is that'. I've never had this problem referring to 'kestrel'.

Computers should have a unique and distinct name. This name should be based on a property of the system that won't change without a system rebuild.

This makes anything based on _physical_ location, or user of the system a bad choice.
Hostnames were originally created as a mnemonic - so instead of remembering that it was or 00:C0:FF:EE:00 you could call it 'frazzle'.
Making numeric hostnames a bad choice.

The only time a numeric hostname should be used is if there's several 'near identical' machines. By which I mean something like a farm of webservers.
So you get web01,02,03 etc.
Essentially, make the number simply a distinction between them, rather than the identifier (the identifier in this case is 'web' and it identifies the cluster of computers).
Similar may be allowable in the case of desktop systems - if your admins are doing the job right, desktops should be basically trivially interchangable. So a desktop called "Compaq-2K-8843" is fine.

Trying to avoid name clashes is also intrinsically a bad idea. After all, most companies have a computer called 'www'. The thing that makes them different is the domain name.

Systems should only _have_ to be unique within their domain. Which is what makes a sensible domain structure essential.

You can have subdomains - i've seen 'dhcp-11-22.coventry.ntl.co.uk'. They name is numeric, because at a general level, all dhcp hosts are generic. And they've broken down their groups in a rational fashion.

So we should always have unique, 'words' as hostnames. Whatever convention you like, be it birds, DND monsters, mr men or whatever. And each machine should _keep_ the name for it's lifecycle.

It should also have an _alias_ for it's function - so the web server for a domain should be "www". Mail, "mail" or "smtp" or similar. This is another situation where sequential numbers are permissable.

But don't name your computers so it looks 'neat' on a spreadsheet. And don't try and make uniqueness across different adminstrative domains. That's just a pain, pointless, and in a worst case confusing.

SSRUG10010 can sound like SNRUG10001 when considered against the background noise of a computer room (trust me, they get loud). Kestrel vs Harpy are never going to have that problem (well, they might, but it's an awful lot less likely.).

So please, check what name your PC at home is called. Make it something meaningful.
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zaitan From: zaitan Date: April 1st, 2004 01:42 am (UTC) (Link)
My machines are named after characters from the Dork Tower comic. My Solaris box at work is called Igor, my test server is called Gilly.

I look after our proxy/cache servers here, they are unfortunately not named very well. The 3 on our site are called pandora, psyche and phoebe! The next one that gets installed by me will have a totally different name. Frank or turnip sound good to me.
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