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An Overview of Virtualization Technology
Jane Walker writes to tell us that TechTarget has a short writeup on virtualization and some of the ins and outs of using this technology effectively. From the article: "Virtualization is a hot topic in the enterprise space these days. It's being touted as the solution to every problem from server proliferation to CPU underutilization to application isolation. While the technology does indeed have many benefits, it's not without drawbacks."
In South Florida tomorrow (Thursday), a dorky looking guy will be presenting an introduction to Xen talk. Check http://www.flux.org/ for details.
You do understand that unless you sign a contract with Microsoft or otherwise make a binding agreement, you have your full "fair use" rights to do with purchased software what you please. Thus, you are not restricted by Microsoft's verbiage found on its website. Don't be fooled by EULA's. They are not enforceable (i.e., binding) unless you agree to them before you make the purchase of the software.
Put differently, if you are the only one using a book you purchased, you can make as many copies of that book you want for your own personal use. And you can attempt to read them all at the same time, if that floats your boat. The publisher has no say in it, unless you signed a specific contract beforehand limiting your usage.
Yeah, I was thinking the same thing. This article would have been interesting, say, 18 months ago... but with VT and Pacifica, things are different now. Without at least mentioning those, it's not very useful.
Anyone have a pointer to a good writeup on the differences between VT, Pacifica, and regular old software virtualization?
FTA: "If you're trying to solve one of the server-based issues like consolidation or application isolation, you'll want to go with a server solution"
Hmm - I think there are a few vendors who'd disagree with that.. Softricity, Altiris, Citrix, Wise to name a few..
Your MS licensing information is out of date. They've changed the way they handle Server 2003. Furthermore, you don't have to use Server 2003 as your base OS for VS 2005. I was using XP Pro SP2, Win'2K Server and Advanced Server, as well as Server 2003 Enterprise during the betas for both VS 2005 and VS 2005 R2. All worked just fine. Actually, I got the best performance from Win'2K AS after I really locked down the services running although that may be somewhat biased as I really know AS best and I didn't lockdown Server 2003 Enterprise. The improved memory model for Enterprise just might give it the edge if it were similarly configured.
"[I]t is a wise man who admits the limits of his knowledge or skill, and that pretending either causes harm." --Terry Go
I virtualized a Windows NT4 IIS server running an ASP application with some VB COM components, VMWare ESX is incapable of running it without insane CPU usage. A one CPU physical server is running at about 30 tx/sec with 15% CPU usage, a virtual server inside ESX is getting 90% CPU usage with barley 5tx/sec, the VMWare host itself is at 65% CPU usage with 4 CPUs.
VMWare seems unable to deal with many object creations and many context switches, the application basically creates a COM object, deals with it and deletes it, very simple logic. A bit disappointing that VMWare is taking such a huge hit.
I agree with you and even take it a step further. The article could not be more plain in that even though it was dated 4/7/2006, it did not take events of the last month into account which makes it totally useless in my opinion.
Three major announcements in the last month have radically changed server virtualization and made the article obsolete:
1. VMWare renamed GSX to Virtual Server and made it free.
2. Microsoft made their Virtual Server free.
3. Microsoft announced support for certain Linux distributions in their Virtual Server product.
The parts of the article that show it's obsolete in light of the above facts:
An open source solution will win the cost battle almost every time
If you want to use Linux as your host OS, you'll definitely have to go with VMware.
Also, for my own personal review - I'm a pretty heavy Microsoft user and was excited about them making Virtual Server free. Evaluating VMWare's free product against Microsoft makes Microsoft look pretty unpolished though. For instance, compare VMWare's P2V application to convert Physical to Virtual servers against Microsoft's offering which requires having a spare server lying around which must run Windows Server 2003 Enterprise with Automated Deployment Services. Give me a break - the cost becomes so prohibitive it's not even worth it. Microsoft may get there but right now their product looks like what it is - a bunch of things hastily thrown together. VMWare's products have coherence.
I'm a big tall mofo.
I noticed that whenever virtualization comes up, no one ever mentions CoLinux. I've tried it once and was quite impressed. It takes a different approach entirely--rather than running in a virtualized environment, it is actually a port of the Linux kernel to run as a Windows process. (Some hardware is virtualized by this method, however, such as the network interface.) Are there any advantages to this approach? In terms of reliability, speed, etc.?
Just curious.
Consolidation technology IS important. And it is "taking off".
Servers are more powerful now. If a company decides to consolidate physical resources (to save A/C, power, rack space, buildings), they can certainly "vertically stack" applications that used to run on multiple servers onto a single server.
However, if this is done with old-hat technology, the system becomes very difficult to manage. For example, I just worked on a 4 way Opteron with 8GB of memory. The NORMAL process list was 1800 lines long!
So, containers are used to segregate the machine into more managable units.
The uptake for this may seem slow, because the clients interested in this have to replace existing gear and facilities. We are talking about major facilities: one client has 7000 assorted Unix, spread across 6 datacenters to be consolidated into 1000 servers at 2 datacenters; another has 10,000 Solaris servers. It takes years to migrate these installations.
Ratboy.
Just another "Cubible(sic) Joe" 2 17 3061
The primary approach we have had to take was to stop looking at whether an app will perform on a virtual machine, and start looking at whether or not it will be cost effective for the app to perform virtually (in general, apps that will perform in the physical world can be made to perform in the virtual world if you throw enough resources at them).
It's an interesting problem. We found that our company's big push into virtualization had to be scaled back a bit - not every server is truly a good candidate for virtualization.
Close... but here's the difference between Xen and VMWare ESX:
Xen does 'para-virtualization', wherein it virtualizes MOST of the hardware, but allows some passthrough to the bare metal. This requires virtualization-aware kernels and modifications to some software, perhaps. Since it's a 'lighter' application than the ESX server, it should run a bit faster.
VMWare does a full virtualization of every hardware component, like most other virtualization products (Virtual Server 2k3, Virtual PC, VMWare Workstation (I'm sure there are others, and I really don't know the field that much), so there is no requirement for the guest OS's (besides x86 and support for the 'VMWare Hardware', which is rather standard). VMWare provides the VMWare Tools package to Windows and Linux servers to enable better communication with the 'hypervisor' kernel, increasing network utilization, etc. However, it is very possible to run other OS's using the standard drivers.
Basically, if you're really going for the speed and don't mind the extra leg-work to get a working kernel in Xen, it should be faster. Since we have to run Windows 2003 servers, and really don't have the staff to hack around the kernels (not to mention already bought support for ESX), ESX runs beautifully for us.