In the corporate and business worlds the use of virtualization has changed the way that hardware is being utilized. For the average PC user we can take advantage of a bit of virtual to allow us some dual or multi-booting without having to make any fundamental or potentially risky changes to our computer.
There are a couple of ways we can take advantage of virtual and perhaps the easiest is by simply installing a specialist program on our machine that can create the virtual environment where we can install another operating system and use it almost as if we were running it normally. We can literally have two (or more) operating systems running at once that we can switch between and use for different tasks.
We can test and get to know a new operating system while still being able to use our current one. We can use a virtual OS to trial software and updates, or use it for general web surfing, knowing that any problems we cause won't affect our main OS. Or conversely we can use a virtual OS just for sensitive logins and banking etc, keeping private data out of and beyond the reach of our everyday operating system. We can keep a virtual OS where we can continue to use older software and programs that won't work in our new current OS. We can also use virtual as a way to run an operating system that might not easily install on the hardware of our physical machine, for example Windows on a Mac or even vice versa.
Some other benefits of this type of virtual are that an entire operating system is packaged up as a single file, which means it is easy to make copies for backup purposes. We can also configure slightly different versions of our virtual OS that we can save and switch over to when required. Amazingly we can even convert our existing Windows OS to a virtual one so we can run a copy of our operating system inside our operating system, or of course from inside any other suitably configured OS on our machine. And perhaps best of all we can transfer our virtual OSes to other machines that we have installed our virtual system in, which means among other things we can if we have made a virtualized copy of our main and cherished operating system have it live on even after the machine it was born on has died or been retired.
It's not all upside however as there are a couple of shortcomings to this way of running a virtual operating system. For starters the virtual OS won't have full or exclusive use of a machines physical hardware, with the consequence that performance will be limited and many graphic or processor intensive applications simply may not run. It is also of course completely dependent on the host operating system that it is running in, which means it can't be used as a fallback OS that we can switch to if we suddenly can't get into our primary operating system. Then there is always the possibility that the virtual system itself could end up causing us a problem in our main OS, thereby making it a liability instead of a benefit. Almost any program that we install in our operating system could cause issues or have a conflict with something else on our machine, so adding new programs is never without some risk. You would be well advised to make a fresh backup of your entire operating system, or at the very least create a new restore point just prior to installing whichever virtual system you choose.
Also bare in mind that with Windows a virtual install needs licensing exactly as a physical install does, so you will need a valid product key either at install time, or for later activation. Most of the other OSes we may wish to virtualize can legitimately be used for free, which includes most Linux distros plus Solaris, BSD and several others. While it is possible to virtualize Mac OS X it is not officially sanctioned by Apple, but it seems they are not against it as long as you have a properly purchased copy of their operating system. The results of virtualizing Mac and some others like Android and Chrome can be problematic and are never really practical for real world use and they are definitely not for the novice to be starting with, so we recommend you stick to Windows and Linux until you get your bearings in the virtual world.
Native Virtual Hard Drive -say what?
First available in just the Ultimate and Enterprise editions of Windows7, the new 'Native Virtual Hard Drive' is a way to run a virtual operating system all on its own without the need for additional emulation software or even a host operating system in which to run it. A Native VHD is essentially a virtual drive that can be installed to and then booted into directly by the Windows bootmanager, thereby giving us a completely standalone virtual operating system that is neither dependent on, nor has to share resources with a host operating system. Someday I'll look into how this magic is achieved, but for now I'll just quietly take what the boffins have given us.
Any version of Windows8 can run 'natively' from such a virtual drive, which means that everyone can now take advantage of this amazing innovation. All that is required is to first create the virtual drive, which entails no more than creating a single VHD file with a few clicks in Windows own Disk Management Utility (from any version of Win7or8). Then we just have to have that file sitting anywhere on our physical hard drive when we reboot our machine from any Win8 install media and after directing setup to use the virtual drive, we carry out a normal and standard Windows installation. The Windows bootmanager will be configured for us and we will get a boot menu at computer startup where we can select to use our original Windows operating system, or our new virtual one.
The standalone and independent nature of this type of virtual operating system means it can remain accessible despite a machine's main OS becoming unbootable. We can also easily make copies of VHD files for backup, or to run clones of the same OS, either on the build machine or on another computer. If we want to return a machine to normal all we have to do is delete the VDH file from the physical hard drive and remove the boot entry in the Windows bootmanager, which takes just a couple of clicks.
Unlike when using emulation software we obviously can't run two operating systems at the same time and so it will require a full computer reboot to change from one to the other. There is no nesting of VHDs allowed, so we can't run a virtual OS inside our virtual OS. Also don't expect full performance from a VHD operating system because there will still be some hardware emulation involved. Hibernation won't function in VHDs and both Bitlocker and Dynamic disks can't be used at all, even on the host computer.
A Fixed or a Dynamic VHD?
When creating your VHD file there is an option to either make it a 'fixed' size, or to make it 'dynamic' so that the size of the virtual hard drive will only ever be the size of the data that is within it. A fixed value of 20gig will mean your VHD file will always be 20gig, and a dynamic value of 20gig will mean your VHD file will expand and shrink as required to the size of the data inside it. This can make for a substantially smaller VHD file, which can make it much easier to copy and backup, but it will impact performance a little bit on slower machines as the file is being dynamically resized, plus if you run out of physical hard drive space to hold an expanding VHD file then there is the possibility of data corruption. A fixed size VHD on the other hand has already reserved all the space it requires on the physical hard drive so there is no danger of it being restricted, and no performance lost to dynamic resizing.
Removing the Win-8 Delayed Touch Screen Bootmenu.