Chuck McManis wrote:
Out of curiosity, lets say you were given the task I've set for myself which is described thusly:
Provide a system that gives shell and email service to a dozen users, hosts perhaps 15 or so mailing lists, provides DNS for 20 - 30 machines.
Preferred OS and what makes it the one you choose?
Ubuntu. All the loveliness of Debian but actually usable in the real world.
Preferred MTA and what makes it the one you choose?
Exim. http://shearer.org/MTA_Comparison
Name service?
Name service?
ssh implementation?
Not really a question. But if there must be an answer then OpenSSH from the distro, remembering to make sure we have the distro's security stream in our package sources.
(If you need more security than this, then you should have the funds to do this properly without asking questions on mailing lists. If you need more security but aren't attracting that revenue stream, then in the wrong game and you need to go home and have are re-think about what you want to do to make a living.)
Hardware?
Rent a virtual machine (e.g. Xen based). This saves you having to make capital expenditure on hardware (= keeps the bean counter happy). Also it means you can do backups to S3 over the backbone.
Now I'll confess that in the way back times I helped start a company that built this exact thing as a hands off appliance for small to medium businesses, the company was called 'FreeGate.' When the domain was retired I believe one of the boxes reported back an uptime of just over 5.5 years for a 48 user, 150 host domain.
I've not generally noticed a problem with uptime these days.
Bill