Why do I need virtual machines?

    I think that at least once everyone has heard that there are virtual machines (hereinafter referred to as "VM").
    Virtual machines allow you to deploy multiple systems based on one computer or server.
    I want to talk about how you can use them and why they are needed.

    If it’s not difficult for you, comment and feel free to ask questions.


    To begin with, I met them a long time ago. I will not advertise specific products, I can only say that I used one of the most common Windows systems;)
    I came to the use of VM due to the fact that on duty I had to support illiterate users of the same Windows, scattered throughout the city. The problem was that users were on different systems. A couple of times I even had to deal with 95 and NT =). But this is not about that.
    We all perfectly understand that it is impossible to remember everything, and when they call you and ask for example: “how can I configure the network settings on win ME” you involuntarily try to remember what is there and how, and you start to fill up the already frightened user with questions.
    Why am I all this, besides the fact that I solved the problem for myself by creating virtual machines with almost all popular OSes, and the questions disappeared by themselves, the necessary virtual machine simply opened, and together with the user I performed the actions necessary to solve his problem.
    The second acquaintance, or rather the second use of VM was found when a powerful server from HP appeared in the office. After a while, it became clear: What has already been put on the server does not use 1/5 of its capabilities, but also what already stood on it (Vin 2k3 with HELL, Exch for 40 computers, ftp, ISA) put into it was impossible, because everything else was on the Nyxes, and at the same time on the terribly squalid hardware of the 90s, as well as what was transferred to the serv from the very beginning. I decided that I could try to correct the situation and make the serv work 100%.
    At first, I put the VM directly from under Windows and deployed 3 virtual machines on it (as an experiment) and transferred some of the niksovods to them (mainly the database, and all kinds of experiments). The next day, surprised employees came to me, asking what happened, that now everything flies like that. I was pleasantly surprised by the fact that on average, even at peak times, the server load did not exceed 40%, and therefore, the next night was devoted to a full transfer to virtual machines. As a result, 7 VMs were created that loaded the server by 80-90%, sometimes up to 98% at peak, and finally gobbled up all the memory. Thus, several problems were solved at once.
    1. Performance stations.
    2. Energy saving
    3. Noise reduction in the admin dwelling - server.
    4. The release of space (a total of 10 computers = departed by departments =))
    5. Convenience of management. (it turned out to be a console) The

    minus is that such systems, in the event of a critical failure, must be completely duplicated, since if one machine is covered (actually our server), then everything falls =), but this did not happen to me.
    Well, the machine should be powerful enough (percent, memory, disks), because everything is distributed between the virtual machines.
    image

    Here is a small illustration showing the meaning of virtualization, only in my case, A, B and C are weak machines loaded at 90-100% and ABC A powerful server.

    Also VM is used by me, for safety, I almost forgot.
    The fact is that VMs can be completely isolated from the Mother OS, that is, you can’t be afraid to experiment with viruses, left-handed software, you can also check your code on them, since a virtual machine is much easier to recover than its main machine, plus it always maybe at hand.
    She can also help the administrator at home: you can safely experiment by creating virtual networks, emulating services.

    admion
    There is another option for using VMs for training, for example, getting acquainted with nix systems, it scares many people that during installation they might accidentally format the hard drive, and installing something new on the VM is safer for the system.
    It can also be used for testing new systems (the same as win7)

    Also popular now: