Naming and labelling
Naming servers after planets is fun until you have thirty of them and somebody has to find one in a rack at three in the morning.
What a good name does
It survives being read aloud, typed under pressure and sorted alphabetically. It tells you role, environment and number without a lookup.
A workable pattern: role-environment-number, for example
web-prod-01, db-prod-01, db-stage-01. Dull, and
it is still legible after three years and two team changes.
Rules worth keeping
- Zero-pad the numbers.
web-01sorts correctly next toweb-10;web1does not. - No characters that are ambiguous aloud. Avoid names where “m” and “n”, or 1 and l, decide which machine gets wiped.
- Do not encode things that change. A name with the rack number or the customer in it is wrong the first time anything moves.
- Never reuse a name. The old one lives on in logs, monitoring and somebody's SSH config for years.
Set the hostname properly
hostnamectl set-hostname web-prod-01
Then make sure it is in /etc/hosts as well, or sudo and a few other
tools will pause on every invocation trying to resolve it. Put the name in the shell
prompt too — most mistakes of the “I thought I was on staging”
variety are prevented by a coloured prompt.
Our identifiers and yours
Every machine we run has an internal identifier — you will see labels like
E11S05 on the front of a chassis. That is what we use to find it
physically. Your hostname is yours and means nothing to the rack.
Keep both in your inventory, side by side. When you open a ticket about hardware,
quoting our identifier means an engineer walks straight to it; quoting only
db-prod-01 means we look it up first. See
hardware failure and
opening a ticket.
Colocation: label your own hardware
If your equipment is in our racks, put a physical label on the front and the back of every machine with the hostname and a contact. When remote hands need to reseat a drive at two in the morning, an unlabelled chassis in a stack of identical ones is a genuine risk.
The same goes for cables. Both ends, every time. It costs ten minutes at installation and saves an hour on the worst night of the year. See shipping hardware to us for how to get it here in the first place.
Keep an inventory
One file, in version control, with: hostname, our identifier, the addresses, what it runs, who owns it and when it was installed. It does not need to be a product. It needs to exist, and it needs to be right — an inventory nobody trusts is worse than none, because people stop checking it.
Still stuck? Mail support@novogara.com — an engineer answers, at any hour. Back to the knowledge base