What should I know before considering a VPS or dedicated server?
I have a plan for the future for an application and web service. The client will have an application that will send requests to a server-side Java backend that will process requests, and the server should also be able to host a website, preferably on a WAMP setup (which is what I'm used to; very little *nix knowledge).
Now, I cannot provide any hard stats because this is only a plan that's in a discussion stage. However, we do fully expect it will scale enough to need some type of dedicated hosting.
My question is this: what types of things should I know about before looking into getting hosting? What should I be asking the hosting providers before I decide on a purchase? When is it appropriate to switch from a VPS to a fully dedicated server?
A few things to ask the company (Especially with Dedicated, but with VPS as well):
Are they using server grade hardware (Server CPUs, ECC memory, Hardware RAID), or desktop grade. For a VPS, I'd stay FAR away from any host that uses desktop grade hardware. For a dedicated server, it's more acceptable, so long as the answers to the rest of the questions are good.
How do they handle hardware failures. Do they have spare parts on site? Do they provision you a new server to use in the mid term? With VPS providers, do they have a "live migration" system in place (where they can move your VPS to a different physical machine without downtime)?
Do they maintain backups, and on what schedule? You'll always want to keep your own anyway, but stay away from a VPS host that doesn't maintain their own backups for free...
What is their SLA policy. Sure, some offer 99.999% uptime, but then when you read the fine print, you only get back like 1% of monthly cost per hour (And they count downtime from when YOU NOTIFY THEM).
What is their upgrade policy. With a dedicated machine, can you "migrate" to a better box without you needing to re-install everything. With a VPS, what's the largest VPS they allow (most CPU/RAM), and can you live migrate to it. If you're on a VPS, can you "migrate" to a dedicated server? Or will you have to reinstall/do it yourself.
That's just a start...
As far as the dedicated vs VPS, it all depends on your application. If you find yourself using most of the resources allocated, or need ridiculous specs, then moving dedicated may be cheaper in the long run. But there's no easy calculator that says "input X, Y, Z and we'll tell you which to go with". It's a judgment call that takes experience to make. Personally, I like to err on the side of less expensive (it's easier to throw more money if you need it, but it's harder to scale back)...
There should be no reason why you can't start with a VPS and move to dedicated if/when the need arises.
I suggest you contact a hosting company that provides both options. Before signing up, discuss this with them and in particular discuss migrating from VPS to dedicated. If they are unable or unwilling to help simply move on to the next one.