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Citrix XenServer Virtualization Platform Now Free
Pedro writes "Citrix announced today that they are giving away their Xen OSS based virtualization platform XenServer with all the goodies included for free. The big highlights are XenMotion, which lets you move VMs from box to box without downtime, and multi server management. The same stuff in VMware land is $5k. They plan to sell new products for XenServer and also the same stuff on Microsoft's virtualization technology called Hyper-V. It will be interesting to see what VMware does. The announcement comes the day before VMware's big user event VMworld."
I like the marketing for this The enterprise-class features you need at none of the cost. I'm thinking this is a pretty big deal.
It's hard to believe that's how Micronians are made. Why don't we see it right now by having you both kiss one another?
Here's the link: Get it while it's hot.
512 MB RAM, 20 GB disk, 200 GB transfer, five datacenters. $19.95/month.
As I've pointed out before, the reason many organizations use VMWare is because it just works. Their stuff is solid, and it works in mixed environments real well. Unless they've made some major improvements, Xen has the problem of being only good at Linux on Linux. If you run Linux servers, and want Linux guests, it's great. However it is not good at Windows as a guest, and of course can't run on it at all. While I've never used Hyper-V, I'm sure it is the same for Windows.
However VMWare isn't a problem like that. You can run VMWare on Windows or on Linux (or Mac for that matter). On either platform, it'll run pretty much anything as a guest OS and run it well. Linux, Windows, Solaris, etc all work great and they've got native tools for most platforms.
That's really valuable to us. We aren't interested in playing around with what OSes we can and can't run on our virtual servers. We aren't interested in fiddling and tweaking to make shit work. We want to install it and go.
There's also a whole bunch of other tools/features VMWare has that are really slick, but the OS support is a big one. Unless Xen gets good at supporting Windows as a guest, and by good I mean no problems, high speed, native tools, etc, it just doesn't compare. Same deal with Hyper-V. It may be the best thing ever for Windows on Windows, but if it's Linux support isn't equally good, then I don't see it as threatening VMWare.
You're describing the practice of using virtualization to host multiple dedicated-purpose "appliances." I use this approach myself; I've got a Debian VPS doing proxy work, another couple of nodes for static HTML serving, another for dynamic apps, one that just serves as an XHTML validation server, etc.
Hardware is cheap these days, and virtualization makes the clean separation of appliances on a single managed box very easy to accomplish. The benefits I get include improved security (difference services run on partitioned hosts) and ease of management (upgrading one application doesn't break others).
512 MB RAM, 20 GB disk, 200 GB transfer, five datacenters. $19.95/month.
A major issue with virtualization in the enterprise is certification by various enterprise software vendors. If your entire platform stack (hardware, Virtualization, OS, etc.) (can you believe we actually have platform stacks now? Geez...) isn't certified, you just give them an excuse to not support you. VMWare has made some solid inroads here, but the last time I saw Xen on the list of certified platforms for something I was integrating was, oh, I'd say never. Not to say such apps don't exist, but they certainly aren't anywhere near what one would call ubiquitous. For many companies, paying the ridiculous price of VMWare is worth it for this reason alone.
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In another move to counter VMware's lead, Citrix will offer its XenServer software free starting in April. One or two high-end features from that product, including the high-availability features, will be moved to Citrix Essentials for XenServer, but many of the existing capabilities will be available for no charge, said Citrix CTO Simon Crosby. Citrix Essentials for Hyper-V and Citrix Essentials for XenServer each will be priced at US$1,500 to $5,000 per server, depending on the features selected, Crosby said.
Enlightenment? It's just a flush in the pan.
How long before we see multiple dedicated-purpose appliances packaged in a single box with the only thing different between multiple models is a license key that 'turns on' the proxy, static web server, router, firewall, e-mail server, etc.
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PBX's have been doing that for a long time now with systems that support Voice Mail, VOIP clients, multi site grouping and routing.
'...if only "Jumping to a Conclusion" was an event in the Olympics.'
1) Requires new hardware. VT is only available on newer Intel processors. So if you have an older server, and many people do, it isn't suitable for that purpose. That will become a non-issue eventually but at this time there are still lots of servers that aren't.
2) In my experience with toying with it, it still has problems with Windows like occasional random crashes and such. VMWare seems as solid as if you are running on real hardware, Xen seems to have additional problems.
Again, it comes down to the "It just works," thing. If you have the hardware that can support it and are willing to tool around and maybe deal with problems, ok then. However if you don't want to do that, then VMWare is what you want.
You're describing the practice of using virtualization to host multiple dedicated-purpose "appliances." I use this approach myself; I've got a Debian VPS doing proxy work, another couple of nodes for static HTML serving, another for dynamic apps, one that just serves as an XHTML validation server, etc.
Hardware is cheap these days, and virtualization makes the clean separation of appliances on a single managed box very easy to accomplish.
At one installation I managed, it was decide that the single (Linux) "server-that-did-everything" approach would be scrapped in favor of multiple virtualized appliances.
Without boring everyone with the details, the "experts" brought in to do this left with tail between legs when it was found that the harware previously used, and which never exceeded 2% CPU Utilization, was woefully inadequate to handle the four virtual machines into which it was virtualized.
New hardware was going to be needed. The manager sent the experts packing, and paid his in-house staff overtime to restore the system to its prior state.
Virtualizing an entire operating system to run a single system for the sake of simplicity is still absurdly wasteful of CPU cycles, memory, and disk space.
NO, New hardware is not cheap.
Anyone who believes it is cheap is looking only at the sticker price and not the staff, power, cooling, backup, rack-space, setup-time needed.
To use the cheapness of new hardware as a justification for virtualization is to turn the whole Virtual Machine concept on its head.
At the end of the day you have to ask: Why vitrualize if doing so means you are going to have to buy new hardware? Just buy the new iron and split out your functions across different platforms and take advantage of the redundancy, and reliability of not having all services disappear do to a single component failure.
Sig Battery depleted. Reverting to safe mode.
This was never true; I'm not sure where you heard it.
very well, actually. I use to host a slew of paravirtualized debian 'machines', alongside a couple of Windows 'machines'.
Xen Server is a nice product - it has good support for Linux and for Windows, and it's fast. I have had trouble setting up a DC under VMWare Server 1.x and 2 when using Linux as the host OS, but no such issues with Xen Server. No clock skew problems, fast networking, easy SAN support, etc.
I had managed to get the tightwads where I work to approve a budget for Xen Server this year (I'm using Xen Express), but now it looks like I'll get to use that money for something else.
Virtualization CAN save money on hardware, cooling, rack space, etc. You have a single multi purpose server. That means that virtualization may not meet your needs. However, take into account the areas where I work, which include a data center that is thousands of square feet (No, this is not a hosting site for web servers, though I have worked for a hosting facility).
Imagine taking into account environments where you need testing, development, pre production, staging and production. Rather than put them on a single machine (Highly unlikely) you can instead buy a small farm of machines, say 20 boxes for multiple applications/environments and then have them pooled into units and use virtual servers of varying priority and power levels. Your staging should have near production capabilities, your dev box, maybe not. Set the thresholds and hardware differences to your liking. However, if each unit was a physical box, even a 1U you would have a lot more rack space required, perhaps multiple node clusters for each, for availability. In a virtual environment, you are pooling physical machines, so at worst, you are overusing capacity beyond your original spec, but the machines should still be available as much as the OS allows.
Your scenario doesn't have any availability for downtime. In mine, if Physical box 11 needs a firwmware patch, I migrate VMs to the other machines and then take P11 offline. I patch it, and rotate in low priority machines to ensure it works as needed. What do you do when you have to go down to the physical machine to patch firmware/bios? You lose all your applications, right?
Virtualizing has overhead on it's own, plus the overhead of running 4 separate kernels, and 4 seperate copies of all the userland shared libs...
Running everything on a single OS image, when correctly configured, gives a pretty significant performance benefit.
Virtualization is more heavily used in the windows world, where it is common practice to have a complete install for a single purpose because a lot of apps don't play well together.
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I can't speak to what happened in your particular scenario, but yes, staff, power cooling, etc. are big drivers for virtualization. I've seen multiple racks of servers condensed down into two servers and a SAN running in about 20U. You can get to everything remotely (out-of-band) without needing an IP-KVM and can restart hung servers without needing an IP/Serial PDU.
Setup time for new servers is orders of magnitude faster. fill out a couple screens in a click-and-drool GUI and you have a new server up and running.
Redundancy and reliability are also quite a bit better. While you're right a catastrophic failure of physical server hardware will bring down the VMs hosted on that server, they can immediately be powered on again on one of the other physical hosts. (Of course if you use local storage with virtual servers, you're playing with fire and will get burned eventually) Virtualization also makes it reasonable to cluster services for HA since you don't need 100% more hardware for failover. VMotion or XenMotion (which I haven't yet tried) will let you move running VMs off a physical box you suspect of failing or need to service which is damn handy, though I don't know that it's worth the price VMWare charges in most cases.
Virtualization means NOT needing to buy new hardware since the hardware becomes a commodity, run it till it fails and then replace it. You get out of proactive replacement cycles and expensive 7x24x4 support contracts. When you need more capacity, you just add another node and redistribute your VMs rather than having to deal with the headache of migrating an overutilized server to new hardware.
Fsck the millennium, we want it now.
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One of the selling points of Unix has always been the ability to have multiple user accounts with security policies that prevent them from interacting badly. The problem, of course, is that security holes are relatively frequent. In particular, local security holes, i.e. exploits in any code that ever runs setuid, are quite frequent. That they're so frequent that people don't trust OS security at all, to the point of running separate apps in separate virtual machines, seems like a pretty conclusive determination that OS security policies have failed.
I can't help but think that one alternate route that would've ended up more efficient would be to give in and write more core software using some variety of language not vulnerable to quite as many buffer overflows and stack-smashing attacks. Doesn't have to be some big paradigm switch like using Ocaml; a C-with-some-safety dialect like Cyclone would be fine. Besides inertia, one of the main arguments against was that it adds overhead compared to straight C. But the fact that people are willing to accept a much larger amount of overhead via virtual machines to get more solid guarantees of security that the OS is frankly failing to provide is some indication that the overhead-for-security tradeoff is something people really do want.
There are some advantages to using virtual machines regardless, such as ability to migrate apps separately. But we're using them here in some cases where multiple users on the same OS really would have been the best setup, except for the fact that we don't trust Linux to be free of local-root exploits.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
We recently did a re-evaluation of our virtualization tech, and VMware won out over Xen. The simple reason: VMware can run Windows on machines that don't have hardware VT. Sure, if we wanted to immediately replace every single server with a new one containing a new cpu, that'd be different, but in this economy you don't really want to throw away perfectly good hardware that still runs VMware at a very nice speed. Xen requires hardware VT, or you aren't running Windows guests, period. VMware doesn't care; it uses hardware VT if you have it, or it does software virtualization otherwise.
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Why not add the service to the existing box? Thats what we ended up doing.
The thing of it is, if you have enough processing power to add Virtualization, you have way more than you need to add the service to the existing box.
I fully understand the big installation guys with a rack full of servers consolidating many into one who have responded here. They are making up for excesses of the past (too much hardware) using the path of least resistance. Instead of learning how to add a service to an existing box they simply clone an existing box into a Virtual Machine, freeing up hardware, some of which is probably obsolete and due for replacement. Its a cost effective approach.
There are also security reasons to do such a thing.
But that's the opposite argument presented by the GP who was talking about the cheap price of hardware as justification to virtualize. That's just wrong on so many levels.
Sig Battery depleted. Reverting to safe mode.
What about the poor bastards like me who paid for Xen? I wonder if they are planning a refund program, or just a life lesson "Tough Shit" program!
"My immediate reaction is "WTF? What kind of moron doesn't make things 64-bit safe to begin with?" Linus
Running everything on a single OS image, when correctly configured, gives a pretty significant performance benefit.
And pretty significant maintenance COST. Running everything on a single OS image means you have to:
a) settle on one OS. you cite windows VMs being common because apps often don't play well together. In my experience, Linux really isn't much better... lots of apps are only vender supported or fully compatible with a limited set of distros or distro versions with specific package version requirements, deviate outside that and your on your own...
With VMs you can trivially run product A in RHEL4 and service B in Debian, and simply not have to worry about it.
b) any time you make a change to any of the services on the image, you have to retest and validate the entire image to ensure nothing broke. If I'm running A and B, and an update to A requires me to update perl or python... and B also uses perl or python than you need to potentially extensively re-test B to make sure it still works.
c) when one of the services load grows its trivial to migrate that service to a new physical server without doing a ton of work building a new image, moving data, testing it, spinning the service down on the old server, etc. Granted, running VMs means overhead that will mean you will have to migrate the service earlier than you would otherwise... but the savings in effort when actually moving it more than makes up for it.
In my experience. of course. YMMV.
I recommend that you need to seriously consider why you are doing it. If you are doing it for hardware savings, you have totally missed the concept of virtualization, which is savings through abstraction. If your site is so small that it can all fit on one server, perhaps virtualization is not for you. However, it still may be for you if you want the hardware availability features (the fact you can take a physical host down and keep everything running on the other, with ZERO downtime). These are the values of virtualization, and they are HUGE especially when you get into larger sites.
Now, Xen vs VMware... VMware does just work, and it is damn stable. And it is damn fast. If you have ever benchmarked VMware Server against Xen, throw your results away, go download ESXi (free) and try it again.
In my testing, with SPECint/fp results (we are an associate member of SPEC), AMD is around 5% overhead and Intel is around 10% overhead. With I/O, you run 10-15% FASTER in a VM than on the exact same physical system, period.