What is virtualization?
The essence of virtualization is running multiple separate servers on a single physical hardware. This provides significant savings in investment and operating costs, improve management, accelerates the creation and deployment of new server and other benefits.
In this article we will talk about the full virtualization, that we are using here in our company. You might have encontred different types of virtualisation in other places, (eg paravirtualization).
Virtualization allows the operation of multiple separate servers with their own operating system on one physical server (on a single hardware). Physical server emulates a virtual hardware to each virtual server(processor, memory, disk, network card, drives, peripherals, etc.). But the customer does not know at the first sight that the server is virtualized. He has his server with processors, memory and other components on it and he is running an operating system of his choice. He has full access to it and work with it as if it is an operating system running on his own hardware.
Why is virtualization a good choice?
It's of course, all about money - When compared to the conventional virtualization solution, it delivers huge cost savings. It concerns the acquisition and operating costs. The objective is to have multiple virtual servers together sharing physical resources.
Imagine that you need to run a few servers in your company - file server, mail server, web server and accounting server. For safety reasons, you do not want all these services running in one operating system, so one possible solution is to buy 4 physical servers. Each of these server has its own physical box, processors, memory, network cards, hard drives and other components.
It is obvious that these 4 servers do not use the whole hardware performance. It is a known fact that the average CPU load average on the server is 15%. The remaining 85% is unused. Regardeless of this fact, the processor consumes several dozen of watts only by just being there and turned on regardless of whether its performance is used or not.
It is a similar situation with the power supply, with server motherboard, etc. These devices consuming several tens of watts just for its basic operation. Although the server will be idle, its consumption is not going to be below 90 W. And the 90 W is not always taken into consideration. - it will cost you about 270 CZK per month, its 3240 CZK per year per server. And of course, you probably have to spend hundreds of thousands on the purchase of 4 physical servers.
The solution is virtualization. Take just one example, For a server of a quarter of the price on which you can run virtualization with 4 virtual servers. They will share the processor performance and also among themselves "split" the cost of running of actual hardware. A significant saving is also noticable on the space where the servers will need to be placed.
New virtual servers are also simple to set up. There is no need to involve any new hardware, it is often a single click in an application. So, the whole operation can be fully automated, saving time and manpower.
Virtualization with us
As part of our service we offer operation of virtual servers on our physical servers. On one server we operate several dozens of virtuals, the final electricity consumption is approximately 4 W for 1 virtual server. This is a crucial difference, isn't it? Thanks to these savings on electricity we can offer our services so cheaply - from 100 CZK month (without VAT).
CPU performance is shared - each VPS has one or more virtual processors alternating on CPU time on physical processors. Read more. VPS - explanation of virtual processors. We do not offer a dedicated processor performance, virtualization would lose all meaning and we are wasting the unused server performance. Then our services would also have to be affordable VPS elsewhere. If the customer insists on unshared performance, he may choose dedcated servers, where the entire physical machine is only for himself.
Memory is reserved - The customer will have the whole RAM ordered for himself. It is difficult with shared memory. The advantage of using unshared memory is in that, the operating systhem running on a vertual server will use unused memory for cushing, thereby reducing the burden of the hardrives. Read more in discussion about file system cache .
We are using this product for full virtualization KVM (Kernel-Base Virtual Machine), running on the operating system Linux. Viz. www.linux-kvm.org. As an alternative, there are products such as VMWare, Microsoft Hyper-V and Oracle VirtualBox.
Not to be confused by mentioned shortcut here is KVM (Kernel-Base Virtual Machine) with another KVM (Keyboard, Video, Mouse), mentioned in the following sections.
On the virtual server it is possible to run any operating system - e.g. Linux or Windows. Operating system can be pre-installed by us according to customer requirements during establishment or customer can install OS by himself by mounting of ISO CD/DVD(see below).
Access to the facilities of the virtual server
A virtual server has the a virtual screen, a keyboard, a mouse, and CD / DVD drive. Since it is about virtual stuff, we need to use appropriate programs in order to be able to access it and use it.
KVM (or Keyboard, Video, Mouse) is a technology that allows access to the monitor, keyboard and mouse of the remote computer. You have to install the necessary software to your home PC, connect remotely to a virtual server and on the monitor of your computer it will be displayed the contents monitor of the virtual server and you can control it to use your mouse and keyboard, as if you were sitting at the server. This is done by a protocol known as VNC. Read more VPS - access to the server via VNC.
It is also necessary for clients to have the option to connect a CD/DVD to their virtual server, from which they want to install an application (or even the operating system). It can possibly be done through the customer administration, where the customer chooses from a list of required CD / DVD and click it to connect to the server. Again, this is solved by the use of a software. As it is about a vertual reality, our technicians have not a physical drive to which to run to and insert CDs. Read more VPS - Connection CD / DVD.
All of that is happening from the comfort of your home (or office) - no need to go anywhere.
On our datacenter website you can find answer to the question ofhow could we offer such low prices. There are details about our facilities, the construction, equipments and the operation of the datacenter. Our datacenter is among the largest and most modern datacenters in the Czech Republic.