This is really something I think people overlook. For a 2 socket server, the total cost for as many VMs as you want is under 8K in licensing for OS, Virtualization platforms, management tools, with little to no limitation.
I run a Hyper-V shop now, and I don't know that I would look back until I hit the performance limitations of Hyper-V. It doesn't make sense, especially if you're running Windows OSes on the HW.
Xen+Xen-tools with Ubuntu 12.04 LTS, unlimited VMs, 2 sockets per server: $0 per server, baby.
Edit: Downvotes? I'm sharing my server setup, which is simple to set up (in conjunction with Puppet), works wonderfully, doesn't involve any bullshit RAM or core/socket limits, and doesn't cost you as much as the hardware in software licensing costs. Sorry if it was a bit flippant, but I think a better approach would be to point out the advantages that these extremely expensive bits of software bring over the free open source software that many of them are ultimately based on.
For Unix workloads, sure, although I'd probably go the RHEL/KVM route. For windows workloads, I'm already buying HyperV, because it's part of windows. So why wouldn't I use it?
A client of mine had several Linux VMs hosted with a company that relied on Hyper-V for their VPS product. Never in my life I saw so many prolems in such a small infrastructure. Volumes would seize and become unreadable, or would become unwritable for no apparent reason. Once, after an outage that lasted more than 24 hours, they had to bring in someone from Microsoft to solve the problem. After this, we moved our machines to EC2. We had some glitches, but none even close to that one.
I know I am not Microsoft biggest fan, but it even seems like their software knows it.
To be honest, I don't understand why anyone uses Windows as a server OS, except for things like Exchange servers. I'd probably not use HyperV because I'd only be running Windows in a container on a Xen machine with primarily linux VMs.
Any particular reason for choosing RHEL? apt-get is so much better than yum in my experience, and if you go with the support contract, you're adding $1,000-$4,500 to the cost of the server over 3 years. That's a pretty substantial bump that I'd rather spend on more RAM...
There is a whole world of energy (Oil) companies, hospitals and finance where $4,500 is a rounding error in IT infrastructure costs. You pay for the support contracts and licenses because A. It's what everyone else uses. B. So when something breaks you can point a finger at the vendor and say "We're waiting on them." It's more about being able to CYA and defer liability than anything.
At these companies IT is a cost center, not a revenue generating department. That is to say, they are structured to where it doesn't matter. Go on Dice.com and search asp.net developers to get an idea of what I'm talking about.
I understand the issue. Even if IT is not considered a revenue generator, when properly managed, it can become a competitive advantage. And since so many companies treat IT as a cost center, subject it to all the "best practices" and use only "best-of-breed" solutions, turning IT into a competitive asset has never been so easy.
The history of corporations is full of examples of not-very-bright companies vanquishing their competition only because they were the least incompetent in that segment and all their competition blundered itself into oblivion.
If it was just one server, that would be insignificant, but that could add 50% to your server costs (if you have a bunch of $10k servers, and you have to add a $5k support contract to each), that can end up being a significant increase in expense.
There are many applications delivered on the Windows platform. .Net platform, SQL Server, AD, ADFS, etc. I haven't cared about OS religious wars for a long time, dollars drive decisions for infrastructure and applications.
Why RHEL? Commercial apps are certified to run on it. Its easier to hire people who know it. There's a manual and vendor guidance who will recommend the "right" way to do things. I'm not going to stand up an application generating a few million dollars a year and discover during an outage that some change in Ubuntu breaks the app.
I love Ubuntu, and use it a lot on my personal projects. But in my professional experience, I've seen plenty of cases where some talented SA sets up a "special snowflake" Ubuntu/Debian environment, then leaves. The company is kind of fucked when nobody understands how things work.
My experience is from enterprise environments. Obviously in startups things are a bit different.
Thanks for the explanation. I'd probably not use any of those services for a greenfield project, regardless of how much money was riding on it.
RE: Ubuntu changes breaking, couldn't this be mitigated by running your own repo and introducing the changes to your repo once they'd been tested on some staging servers? It may be a moot point, though - I've never had a Ubuntu update break an app, and I've found LTS to be very stable. And if there was an issue, I've always got a backup image I can revert to.
Fair wrt the SA thing, it can be very janky in startups and SMBs, but in an enterprise, I'd expect most server deployment to be automated in a sane way, is this not the case?
Usually, a sign of a well run enterprise IT environment is infrastructure builds driven by vendor recommendations, but customized by a deep understanding of the vendor's bugs and other strategic factors. On the procurement side, they make deals to keep costs in line. No Fortune 500 is paying $1,300/socket per host for RHEL -- they're wheeling and dealing site licenses that probably end up being similar to the Microsoft model of $X/socket for unlimited VMs.
For example, Microsoft hands out lots of useless sizing guidance by assuming that you use physical hardware and JBOD disk. Good Windows admins/build engineers test the actual limits on their environment and size appropriately, and get the vendor to sign off.
Enterprises are all about risk mitigation. Usually that means (Product X broke because vendor Y told us to deploy component Z wrong.)
Yeah, Windows in itself doesn't seem like a very good reason to drop $X,000 more per server on a commercial virtualization solution vs. just going with Xen.
I run a Hyper-V shop now, and I don't know that I would look back until I hit the performance limitations of Hyper-V. It doesn't make sense, especially if you're running Windows OSes on the HW.