How to install and configure Xen Server

Xen Server is a specialized platform that uses hardware virtualization technologies in its solutions . It should be noted that in this case it is impossible to find any cardinal differences from the program procedure, but the performance is quite comparable with the productivity of a real machine, which made this base so popular for use in an industrial environment.

What are the advantages?

Among the main advantages of using Xen Server is the following:

• A significant reduction in the time, as well as the laboriousness of the development of virtualization systems, which is provided by providing hardware interfaces for managing the necessary guest systems.
• Providing users with the opportunity to significantly increase the performance of virtualization platforms due to the fact that the management of guest systems is carried out through the hypervisor directly.
• Such platforms are much more protected from external interference, because They use an extremely clear separation of the virtual machines themselves, as well as the hardware resources used. The work of each platform is carried out in full independence from other equipment, that is, all units function in their space using individual resources.
• Among other things, Xen Server is not platform independent of the created guest systems from the host computer.

What is he like?

Xen itself is a cross-platform hypervisor. This platform is a unique development, which belongs to the University of Cambridge and today is distributed exclusively under the GPL-license. Initially, supported by two main branches of the product - the commercial version and the version with the source code, but in 2009 it was said that all versions of Xen Server will be completely free, that is, the resource will be free.

The main idea of such a hypervisor is the domain, that is, a previously running version of the virtual machine. In the event that it starts to reboot, the domain is completely terminated, and after a new download, a new one is formed. Even during the migration, the Xen Server content will be copied between them. Due to this, virtually every virtual machine ends up being in the queue in various resources in the process of its existence, however Xen operates only directly by the very concept of the domain, and everything else appears only after it comes to providing administration of application programs providing control over Hypervisor.

Why is the system so common?

To date, we can safely say that Citrix Xen Server is one of the most powerful systems with support for hardware virtualization. It should be noted that it remains the fastest and most secure among all the types presented, but it is completely free product. However, of course, it can not be said that this solution is recognized as absolutely universal, and therefore, in some situations, users may also resort to other types of software.

How to install and configure it?

Citrix Xen Server is designed to provide more efficient operation of standard operating systems Windows and Linux. It should be noted that you can also use other variants of platforms, but the manufacturer does not give any guarantees that they will be marked with normal work.

Download all the necessary files you can from the official website of the developer, while we recommend that you familiarize yourself with the main terms of use and the license agreement in advance. After you download the Citrix Xen Server and write it to a specific drive, you can connect the device to the computer and start working. It is worth noting immediately that in the process of this installation, any data that you stored on your disk will be completely deleted, therefore you must take care in advance to ensure the safety of important information.

Then you will see a screen that prompts you to install Xen Server 6.2 (or a different version if you downloaded it). After passing through simple installation steps, a final window will appear, indicating that the platform has been installed correctly.

After the Xen Server is finally downloaded to Ubuntu Server or other types of user platforms, it automatically switches to the main window of the already running system. It looks like a full-fledged main menu of the loaded Xen system, and it is divided into two columns, where in the left one you can select the basic parameters by using the arrow keys, while in the right one all relevant options will be displayed, with which you can Change certain properties of the running system. To switch to this change, you need to select the desired item and click on Enter.

While you are in the Xen Ubuntu Server control window, you can use the Alt + F3 shortcut to go to the standard Linux console, which again proves that the platform itself is a standard Linux equipped with its utilities, and Also understandable and well-known set of commands. It is for this reason that for those people who own the Linux operating system, there is nothing difficult in getting to grips with the basic features of this platform.

Configure the system

After you start this server, you can look at the two main links using the appropriate address in the browser. One by one you will be able to download XenCenter, which provides full control of this platform, while the other is an exe file. Either way, after installation, you will see the management console, after you enter your own host address in it, as well as the root password, and you will be granted access to the system.

We get the basic information

In the standard mode of the running host, you can view both statistical and technical information, and by traversing the tabs at the top you can also get access to a lot of other additional ratings and parameters. For example, in the Performance tab, you can see the basic information about how far the Xen Server host has been loaded, which has just been deployed, and how free resources are used.

Installing the guest system

If you want to host the guest system, you will need to go to the New VM item or just the VM, and after opening this menu item select the operating system that you are going to install as a guest. In particular, if you prefer, you can also install Xen Server in Windows 7. It is worth noting that this platform offers quite a wide variety, and the installation procedure is almost identical to that used in VMware Workstation. That is, the process is divided into several main stages:

• Definition of the type of system;
• Setting the required number of processors and memory;
• Freeing up space on a hard drive or a specialized data carrier for installing a new system in it.

If you once had experience working with VMware Workstation in your life, you can be sure that you will easily understand the main functions and you will easily configure and initial installation of Xen Server on Windows 7 or other types of operating systems.

What to do next?

After you create and start a new machine, the procedure turns into a completely standard installation for the operating system that you choose. And here there are no completely new elements. You just have to wait until the installation procedure for the new system is finished, after which you can fully use the functions of the Xen Server console. Deploying VDI or running any other mechanisms - all of this is now within your capabilities, and you can use the system as you see fit.

Hardware

Do not forget that the operation of the system directly depends on the hardware you are using. It is for this reason that the primary task before creating any cloud is to provide servers on which the virtualization procedure will be implemented.

In order to ensure a fairly rapid migration between different IBMs in the stand, a dedicated switch is used, which in theory makes it possible to accelerate the migration by a factor of 10, but in practice this acceleration is an order of magnitude smaller. In order to provide access to the local network of servers and virtual machines, an additional switch can be added to the stand, with the help of which traffic to external clients will be transmitted.

In addition, it is also important to use uninterruptible power supplies, which will ensure the correct recovery of processes on the server in the event of a failure of the central power supply.

How do I host a server?

Next, the question arises as to where exactly the virtual machines will be stored . In the event that they will be located exclusively on the servers themselves, this will negatively affect the overall reliability of the entire system, since in the event of any malfunctions, you will automatically lose all the virtual machines located on this equipment.

Among other things, do not forget that using this approach will also greatly complicate the overall task of load balancing, since to ensure the migration of the virtual machine it will initially be necessary to move its drive to some other server, and this will create a rather long and tedious Procedure.

Create a virtual network infrastructure

In order to ensure the ability to flexibly manage the network settings of virtual machines, and also to ensure that they are not on the same subnet with "Xen Server", you will need to build a virtual network infrastructure. In this case, Citrix originally provided such a problem and developed DVSC, which also appears as a virtual machine, but already consumes much less RAM and resources.

If you go directly to the DVSC web-interface, you will find there a lot of useful information about the network infrastructure, including the list of virtual machines that have now managed to connect to a certain network, all kinds of error messages, and network activity graphs Only for a particular virtual machine, but in principle for the entire network.

You can also use DVSC as a standard firewall, the rules of which can be set through the AccessControl tab. The network security policy is divided into four levels, and the rules allow you to describe a specific type of action, a protocol (in which sender and receiver ports can be specified, and known protocols can be specified), and also for whom this rule will be applied.