Why would you need Virtualisation?

If you have gone through the previous article describing a typical scenario for virtualisation usage, you  can already have a sense of the answer here. Still, it is worth looking at the profits you can get from virtualisation.

Basic advantages of virtualisation

Right off the bat, the top four benefits you can reap of are:

  • saving power;
  • hardware consolidation;
  • system management and security;

Saving Power

Before the virtualisation, in reference with the X’s scenario, he would not have much choices and would have to setup each operating system on unique physical system. Since virtualisation is out there, now X could setup multiple web servers or clients on a single physical system, reducing huge electric consumption substantially.

Rather than one machine running a Windows File server and another windows system for DNS server and another running Linux for DHCP server, use one physical system and setup system for that handle all three of them. Imagine if each of the system had consume 300 watts of electricity how much three or more of them would consume each day? Whereas you can potentially cut down the consumption to just one 300 watts of electricity consumption.

Hardware consolidation

You can save power by consolidating multiple web servers or clients into one single powerful server or client, you which also helps you avoid the cost involves purchasing expensive hardware which may rarely run at its full capacity during its entire lifetime. With the durable thin clients, complex desktop computers can easily be replaced, which may not even require additional physical components like hard drives, fans, optical drives since they only need enough power to access the server. For such a case, why would anybody buy the whole multiple high-end servers, multiple processors, RAID arrays, redundant power supplies and so on so forth. A simple implementation of virtualisation, you build one physical server machine and run multiple servers or clients, which eliminates all of these potential direct business cost and overheads.

System management and security

One of the most common benefits with virtualisation is reaping from the easy-to-manage systems. You can take the full advantage of the fact that VMs are simply like files like any other files, can be copied. Any new employees can quickly setup virtual machine with department-specifics including all of the software that is already installed.

This kind of management system turns out to be a sleek security advantage as well. Let’s say you have put a new employee with a physical system. In case that system goes down for some reason like – hacked, malware and likes – you need to restore the whole system from a backup, which at worst, may not be even easily available or break out the operating system’s installation media. If a virtualisation has been setup, the host machine, hypervisor and any other VMs it runs fortunately are, generally, unaffected and uninfected. You just need to shut down the virtual machine and reload another clean and alternative copy of it. That is it. Since, VMS are simply files, they are easy to keep around and mange and backed up.

Yet, note that we mentioned “generally” here since VMs are connected to a network, which face the same risk factors as any other networked computers. All networked VMs have security requirements, which are similar to a physical system and definitely should get the kind of security system you would implement in a physical system. VMs still need a good amount of security measures and hygiene.

Most of the virtual machines out there give us the option to make a snapshot or checkpoint which saves a copy of the virtual machines state of that point of time. This incredibly allow us to quickly revert back to that state when we need it.

These snapshots can let you take risky measurements, maintenance with a safety net or updating, without having to worry about if you could ever go back to such state before. However, these measures are not long term strategy for backup since each of these snapshots can significantly reduce performance and should be removed as soon the threat is passed.

Note that each of these virtual machines have same behaviour or tasks available to you as of any other physical system with any operating system. So you could manage machines multiple user accounts with their respective user name, passwords, permissions and so on.