Forgive me if this has been asked and answered (I was surprised that I could not find a thread or two), if this has been discussed, please point me to the thread(s).
I would like to set up a test server in my home. I have a Linode 540 and I don't want to purchase a 360 for a test environment. I would really like two test environments, one to test OS and major service upgrades, like upgrading to Ubuntu 10.04 LTS when it is released, or switching from apache2 to nginx, and one as a final test before moving web changes to production (I develop on Macs and there are enough inconsistencies to warrant a separate test environment).

So what I need is the ability to duplicate my linode environment on another server, preferably using a vps solution so that I could migrate an image from test to production, is this possible? If so what would I need. I have a suitable machine: 2.66 Quad core intel box with 6GB Ram. I know I could install Ubuntu on it and configure it like my linode, but I would prefer to run several VMs on it and having the ability to transfer an image to or from linode would be very helpful.

Please recommend an OS and a VM or VPS implementation.

I believe various ways of doing this have been discussed in the past, although IIRC each one requires some significant setup and aggravation, and is never an exact duplicate of the Linode setup.

Are you aware that buying a new Linode is not a commitment? When you want to upgrade your Ubuntu, buy a new Linode, clone your old one to it, upgrade the new one, try it out for a couple of days, and when things look good, point your external IP to the new node and dump the old one. (I believe all that's possible.) Or else perform the same steps on the old node and dump the new one.

The additional Linode is pro-rated to what you actually use, so you're only out however many days' worth of Linode, not a whole month.