You may have heard about a new web hosting option coming to EPhost soon called Virtual Servers (or server virtualization). I wanted to take a moment and explain virtual technology, and explain the differences between it and another technology called Virtual Private Servers (VPS).
VMWare Virtual Servers
You can think of virtual servers as a server within a server. A virtual server is an independent isolated operating system that lives inside another server. Multiple virtual servers can reside on the same physical server. Usually they are referred to as the Host system (physical server) and the Guest OS (virtual server). Each virtual server operates entirely independent of one another and for the practical part independent of the Host System. What makes this situation so unique is that there is literally no difference between a virtual server and physical server– not to mention that the same physical server can host many virtual servers.
What makes this possible is a lightweight operating system that is pre-installed on the Host system (physical) called a Hypervisor. The hypervisor is responsible for dishing out the physical resources like CPU, RAM, NIC and HDD space in a specific manner to the independent Guest OS’s. You can think of it like a layered cake with the hardware at the bottom, the hypervisor next, and the guest systems on the top. There are several hypervisors that are currently available. The two primary ones right now are from VMWare and Microsoft. Microsoft calls it Hyper-V and VMWare calls it a Hypervisor. Currently the both are competing for market share. At EPhost we currently use VMWare, but we plan to use Hyper-V as well.
What’s make this possible overall has been the creation of multi-core CPUs that are optimized for virtual servers. Mutlti-core CPU’s are very similar in that the same physical CPU is actually a collection of 2-4 cores each operating as its own CPU. To the operating system, it actually sees multiple CPU’s even though there might only be one physical CPU. You should note that the number of cores is not directly related to the number of virtual servers. So it’s possible to have 20 virtual servers using the same 4 cores.
The net result, no pun intended, is the ability to have many virtual servers within the same physical machine. This provides a number of benefits. First, it gives rise to the consolidation of networks, thus reducing CO2 emissions required to power and cool servers. Second, it provides an excellent platform for users to quickly deploy server environments, makes it easier to migrate servers, and offers the ability to host various OS types such as Microsoft Windows and Linux Red Hat on the same machine.
Virtual Servers can also be used as Virtual Desktops allowing companies to deploy and destroy employee workstations as needed. Employees, will use thin-client computers to transparently dial in to a central server to see their normal desktop. This keeps information secure and reduces valuable IT time required to deploy a work station.
Virtual Servers shouldn’t be confused with Virtual Private Servers (VPS). While they are sometimes used interchangeably they are different. VPS based environments are similar in that they provide an isolated OS environment to the user, but they ultimately rely on splitting a single operating system into several parts. A well known vendor of VPS technology is Virtuoso by Parallels. Parallels is known for making the self-titled software that allows MAC users to switch to using Windows on their MAC. The primary difference between the two is that virtual servers are divided up at the core hardware level (using the Hypervisor) making better use of resources, while VPS is done at the software level.
At EPhost, we’ll be using real Virtual Servers and NOT VPS technology to drive our consolidation efforts, and to offer dedicated servers at a lower price point. We will continue to provide standard hardware-based dedicated servers for those that need all of the server resources. However, using Microsoft’s Hyper-V technology we will also offer the ability for dedicated server customers to virtualize their physical server to make better use of resources.
Tags: virtual servers
