With the VMware-sponsored VMworld extravaganza in the rear view mirror, it's a good time to take stock of the server virtualization that companies around the world are deploying - to remind everyone that there are lot of different ways to skin the server virtualization cat and that plenty of alternative skinning is going on out …
Performance / ESX / VMware
ESXi has rather narrow hardware requirements, and the new management and consoles of both VMware 2.0 and ESXi are weak at best. Having an actual full blown OS underneath your HV adds a bunch of flexability to your mix. VMware currently has the market because it's tools were much better, and it's products were more stable. The latest console fiasco is stunning IMNSHO.
VirtualBox (Sun) allows one to set up headless VM's that console connect from any RDP client. This is a Huge win IMHO. Further I've found I can run VirtualBox and a couple of VM's on very modest hardware, like a 1.6 Atom with 2GB of RAM running Slackware and XP on top of Ubuntu9.04, something I was flat unable to do with VMware. Someone enlighten please, Will Microsoft's product run anything but Microsoft software? I would truly be suprised if it did.
Long term if VMware wants to hold market share, they need to lose the sorry console client, and do something about the performance. VirtualBox is not there yet, but a little polish and it's going to eat VMware for lunch. I've re-scripted the startup/shutdown for VirtualBox, and have 7 VM's running on some heavier hardware. I think VMware is getting the IBM throw more hardware at it mindset., where you add more blades.
We're currently virtualising a large portion of our estate to cut down on both space and power requirements. Unsurprisingly using VMWare to do the job - but it makes it so easy to do. The new VSphere release has some nice features although we have picked up on a couple of minor bugs (nothing show-stopping).
We tried out a couple of proof of concept solutions of other products (Parallels Virtuozzo for example) but found VMWare to be much more polished. It's not really a great surprise to me that so many companies use the VMWare route as they seem to have got their package "just right", at least by our experience.
"VMware's ESX Server is used by 60 per cent of the companies polled, and the freebie ESXi hypervisor is used by 31 per cent of companies. A little more than a quarter use Microsoft's Virtual Server (type 2) or Hyper-V (type 1) hypervisors, and the XenServer hypervisor is used by 18 percent of companies"
So according to this paragraph, 109% of companies polled are using a hypervisor of some sort. 109%? I never studied statistics but how does this make any sense? Furthermore, if you total the percentages on the graph in this article it comes to 213%
Wtf? is this like an election in Zimbabwe where they routinely have 150% voter turnouts, of which 180% vote for Mugabe?
How many people tried to virtualize and found out that running on real iron is better for the particular application that they run.
In my experience I have found that going the virtual route is mainly expensive. Virtualization does wonders for small applications with low yields requirement, but it ruins citrix and exchange servers, specifically because very low I/O compared to the real thing.
So far I've tried vmware, sun's vbox, xen and the citrix xenserver, and the results are all the same, very comfortable environment to run but very slow I/O. Domain controllers, small db oriented apps, even the odd MS-SQL test server run just fine, but anything else that requires raw power does not.
I do not know about Linux servers though, never had to virtualize any, the buggers keep running fast no matter what you throw to them.
Mine is the coat of the non-international-enterprise it worker. Yes the one making redundancies without thousands of pounds to burn in software licenses.
re: Keith Smith 1
"Having an actual full blown OS underneath your HV adds a bunch of flexability to your mix"
In what sense? Surely it is better to have a type-1 hypervisor that talks directly to the hardware without needing an OS to run it (the hypervisor)? In terms of flexibility, you're type-2 hypervisor (the one you describe) would need to have drivers embedded in the host OS to run the hardware akin to how hyper-v's parent partition needs them.
I don't see how this can be more flexible than a type-1 unless you're talking about a situation whereby the hardware you want to run the type-1 isn't on the HCL. If it isn't then you shouldn't be trying to use that piece of hardware.
Performance on a hosted hypervisor will be pants when compared to bare-metal, you won't be able to scale as high as bare metal, and you have a host OS "translating" between the hypervisor and the physical devises.
VMware are market leaders in this game, ergo, people like to take pot shots at them. VirtualBox will NEVER eat VMware for breakfast. Solaris was always better than Windows but did Solaris eat it for breakfast? Of course not.
With regards to Hyper-V, it runs Novell (Suse) Linux and Windows. That's pretty much it. Microsoft claim they will run more Linux flavours but I can't see it really happening.
VMware runs by far and away the MOST Operating Systems out there, right down to DOS IIRC.
Not sure about OS2 though ;)
Have virtualised our entire estate into a handful of vmware boxes and it's just so simple to manage. It does help that we have some truely blistering nfs performance from our Bluearc NAS to ensure we don't end up with that storage bottleneck problem everyone else seems to have.
Another vote for Sun's VirtualBox
My main home rig (Core2-quad, 8GB RAM) runs Fedora 11, but there are a couple of Windows apps I haven't found the Linux equivalent for, and for which WINE doesn't suffice. I installed WinXP on a vbox VM, and I agree with Keith Smith. Vbox has "just worked" since I first tried it. It uses one core and 2GB RAM, and performance is lickety-split. I'm a little apprehensive about what Oracle will do with VirtualBox, but as long as the current version works on Fedora, I'm happy.
Fair question…. the percentages cited from the survey reflect % of respondents that are using that specific platform. The numbers exceed 100% due to the fact that the majority of survey respondents have a heterogeneous environment with more than one hypervisor/virtual platform in use.
In fact, one of the key findings in the survey is that only (approximately) 4 out of 10 companies have standardized on a single virtualization platform. The remaining 60% are using 2 or more different virtualization platforms.
See http://www.centrify.com/resources/survey.asp for more details of the survey.
I'd be more interested in seeing the numbers on how many virtulization technologies companies are using. Here we're using HP vPars, Sun containers and VMWare for Windows / Linux. We pick the best technology for the job, but always with an eye to virtualise that technology where possible.