The “Virtual Machine” is now quoted at every opportunity. Many normal PC users, who only need the computer as a tool, may not even know what that is. We explain to you very briefly what a VM is, what it is good for and then show step-by-step how a VM is set up, whether for/under Windows or Linux. And for after the installation, we still have the most important tips for optimization:
What is a virtual machine?
Virtual machines are simulated (even if the term is not entirely technically correct) computer hardware that operating systems such as Windows can access in the same way as real hardware – Windows does not even realize that it is running on a virtual machine. A virtualization program like the free one VirtualBox So creates such a VM, which in itself is nothing more than a small configuration file that says how much memory the VM has, what graphics card is used, what kind of network connection and what storage media are connected. VirtualBox will boot using this configuration file and you will see a black screen like the real machine. As a storage medium, the VM uses a virtual hard disk, an empty container file that behaves like a real disk. On the other hand, the VM uses ISO files, which are “inserted” just like real CDs/DVDs – only that “insert” means “embed” or “mount” here. If VirtualBox now boots with the ISO attached, for example from the Windows installation DVD, it starts from the CD just like a real computer and you can install Windows 1:1 on the virtual hard disk like in real life. At the end of the procedure, VirtualBox starts the VM and you see a window in which a complete Windows or Linux is running.
What is all this for?
You can do all your work in the VM and create extremely simple backups - VirtualBox can clone VMs and create snapshots and in addition your whole computer consists only of the configuration file (a plain text file) and the virtual hard disk, which you can of course back up as you wish and also can start on any other system. If you play the two files and the portable version of VirtualBox on a USB stick, you always have your entire computer in your pocket - including media, mailboxes, Office and so on. You can also safely test dangerous software, viruses, worms and Trojans, create a system for guests, test Linux and much more - and all systems can be restored to their original state or any snapshot at any time. In other words: Virtual machines are also practical for noobs, DAUs, beginners, laypeople and average users - and set up very easily, here with Ubuntu as a guest system (i.e. in the VM) and Windows 7 as a host (real computer):
1. Install VirtualBox
First you install VirtualBox and start the assistant with the "New" button.
2. Create system
When assigning the name in the next step, you should use the name of the operating system to be installed - VirtualBox then immediately sets sensible defaults, which you can also change in the next steps.
3. Determine RAM
If you have a lot of physical RAM, give the machine a gigabyte or two, it benefits from it just like real computers.
4. Mount hard disk
In the next step, you determine that a new hard disk should be created. You can ignore the size specification.
5. Determine disk format
If you don't want to use the virtual hard disk in any other way than in VirtualBox, simply stick to the standard, VirtualBox Disk Image (VDI) when choosing the format.
6. Type of storage
Select "dynamically allocated" as the storage type. This means that your virtual hard drive offers around 40 gigabytes of space, but the container VDI file is only as large as this space is actually used. After installing Ubuntu, the VDI file would be just over 1 GB in size. If you then boot the VM and create a 2GB file, the VDI would grow by those 2GB. If you chose "fixed size", the VDI file would be 40 GB in size from the start.
7. Set disk size
And that's exactly why you can lay out the size generously - it doesn't hurt.
8. The VM in the manager
The virtual computer is now complete and you can find it in the main menu – the “CD” with the operating system is still missing.
9. Mount OS/ISO
To insert the Ubuntu ISO, you open the settings of the VM via the context menu and the entry "change", switch to "mass storage", click on the CD symbol for "Controller: IDE" and then open via the small icon on the right in the picture the entry "Choose file for virtual CD/DVD drive".
10. Select ISO
Select the downloaded ISO file, here Ubuntu 12.04.
11. The ISO in the manager
Now you can see that the IDE controller recognizes the Ubuntu CD as inserted.
12. Start VM
Now start the machine from the main menu.
13. The calculator on the desktop
If everything is fine, the VM will now boot from the Ubuntu CD and you can test or install - it's also good to see here that a VM is just a perfectly normal window.
14. The running system
Once booted, you can use Ubuntu exactly as you would on a real computer. In full-screen mode, the uninitiated cannot see at all that they are sitting in front of a virtual machine - however, this should not work at all yet, the Ubuntu desktop is very small by default. The so-called guest additions must first be installed under Ubuntu, which adapt the operating system for operation in a VM and, among other things, ensure full screen resolution. You can find the link to the instructions in the tips above.