Energy Drinks

Check out Energy Drink Reviews at http://www.energydrinksblog.com/. Read about Monster, Red Bull, Amp, Rock Star, and many other caffeine-loaded drinks.

Operating system-level virtualization - high level overview

Wikipedia has a solid overview of types of virtualization. Specifically, here on the operating system level:

Operating system-level virtualization

Operating System-level Virtualization is a server virtualization technology which virtualizes servers on an operating system (kernel) layer. It can be thought of as partitioning: a single physical server is sliced into multiple small partitions (otherwise called virtual environments (VE), virtual private servers (VPS), guests, zones, etc.); each such partition looks and feels like a real server, from the point of view of its users.

For example, Solaris Zones supports multiple guest OSes running under the same OS (such as Solaris 10). All guest OSes have to use the same kernel level and cannot run as different OS versions. Solaris native Zones also requires that the host OS be a version of Solaris; other OSes from other manufacturers are not supported.^{[citation needed]},however you need to use Solaris Branded zones to use another OSes as zones.

Another example is AIX, which provides the same technique under the name of Micro Partitioning.^{[citation needed]}

The operating system level architecture has low overhead that helps to maximize efficient use of server resources. The virtualization introduces only a negligible overhead and allows running hundreds of virtual private servers on a single physical server. In contrast, approaches such as pure virtualization (like VMware) and paravirtualization (like Xen or UML) cannot achieve such level of density, due to overhead of running multiple kernels. From the other side, operating system-level virtualization does not allow running different operating systems (i.e. different kernels), although different libraries, distributions etc. are possible.

Main article: operating system-level virtualization

Virtualization Review writes an open letter to VMware, Microsoft, and Citrix

This is an excerpt from the full letter on http://virtualizationreview.com. They make a few great points that VMware would do well to heed.

VMware: I like what you're doing. Unlike Microsoft and Citrix, you focus 100 percent of your efforts on virtualization, and because of that, you continue to lead the field. VMware View is coming along nicely, and you're making progress in brand-new areas like taking virtualization to the cell-phone and smartphone level. Your latest financial quarter provided a boost, demonstrating that the vision of CEO Paul Maritz is paying off.

Still, too often you act as if there's no competition. I hear many complaints about the expense of your solutions. You usually respond with, "You get what you pay for." Well, that argument is outdated. If you need evidence, I refer you back to our cover story, which shows that the hypervisors of your two main competitors stack up well against yours. In fact, I know more than a few admins who are taking a serious look at the alternatives. They all give one reason: price.

Remember that Microsoft and Citrix are combining dev forces, and every single product they produce in this space costs less than an equivalent VMware offering. Also keep in mind that Microsoft, especially, is spending tons of cash to narrow the gap with ESX and Virtual Infrastructure. Some customers don't worry about budgets, and will dole out whatever's necessary to get the best, which-for now-means going with your stuff. Currently, however, we're in an environment where that demographic is shrinking rapidly. I don't believe you can sustain that attitude for much longer, and I can see Microsoft making inroads faster than you expect.

How to Install VMware Server

What you need to know prior to installation - from http://www.petri.co.il/virtual_install_vmware_server.htm - visit the site for screen shots.

VMware Server will only run on Intel machines. The host operating system can be Windows or Linux. This article assumes you are using a Windows XP machine as the host operating system. The most important thing you should know about installing VMware server is that it will use significant amounts of your RAM. You can control the amount of RAM allocated to running virtual servers but it will require a minimum of 256MB per virtual server. Only allocating that much to the virtual servers may be good for your host operating system but will be bad for your virtual servers. Of course, the RAM requirements depend on what you are using the virtual servers for and if you are using the host operating system while you are using the virtual servers. In the end, you need a lot of RAM on your host system to use virtual server. Fortunately, RAM isn’t that expensive today so I would just make sure you have at least 1GB of RAM to be able to run 1-2 virtual servers. Also, remember that you are running other servers inside your host machine. That means that other things like CPU and disk will also be pushed to their maximum. Even with a lot of RAM, you can easily max out your CPU utilization. Keep these facts in mind so that when your machine slows down, you know where to look. Another tip is just to remember that your machine is not invincible. With a standard desktop today and 1GB of RAM, your performance will seriously suffer if you start more than 1 virtual machine and try to use your host OS at the same time. You can probably run more machines with more RAM but you still need to make sure you limit the number of machines you run at the same time.