The benefits of virtualising OS X

As you may know, I regularly contribute tutorials and reviews to Mactuts+ and Mac.AppStorm. One of my more recent guides was How to Install and Start Using OS X Server. This detailed the process of installing OS X Server, from downloading it from the Mac App Store to installing and configuring some if its basic services.

Now, I don’t have the luxury of multiple Macs at home. In fact, I just have one – an 11” MacBook Air. This is the machine I depend on daily so if I can avoid installing any software that I won’t be using regularly, I do.

Instead of using my own Mac for situations like this, I actually make use of a virtualised OS X environment with Parallels Desktop, and there’s a number of reasons why.

Firstly, if I install a particular piece of software that is going to make major changes to, (or potentially breaks) OS X for whatever reason, it only affects the OS X environment within Parallels. I’m completely free from the worry that making a huge change to my Mac is going to cause me problems further down the line since any changes are made within this virtualised version of OS X. If I end up completely breaking this version of OS X, I can just start again. It’s like having a spare Mac that you can do whatever you need to, knowing that your primary Mac will remain unspoilt.

In addition to this, Parallels has a great feature called Snapshots. Once I get my virtualised OS X installation exactly as I want it, as well as up to date, I take a snapshot. Once I’ve finished writing a tutorial or reviewing a piece of software, I just roll the snapshot back and it reverts within seconds, erasing any trace of the software I just used. It’s similar to restoring from Time Machine every time you wanted to uninstall an application but it takes only a few seconds and, again, all resides within Parallels. You can also have as many snapshots as you have space for.

If you have a 13-Inch Retina MacBook Pro then you can’t run OS X Lion natively, it doesn’t contain any of the required drivers and predates the version of OS X it shipped with. However, with Parallels or VMWare Fusion, you can. In fact you can even run Snow Leopard Server if you wanted. This isn’t much of a use anymore now but I do still have a Lion virtual machine set up just in case.

Since my Mac has 8GB of RAM, I’ve found no problems running multiple virtualised OS X environments. It gets a bit cramped if I run two versions of Mountain Lion at the same time since it’s more about the processing power than available memory, but it’s still usable. What’s more, this gives me the ability to emulate having multiple Macs. I can run an OS X Server environment in one window and have an OS X environment interacting with it in another, all without involving my real OS X installation at all.

My current list of Parallels virtual environments

Taking a look at my screenshot above, I have a number of environments set up. There’s one for Windows 7 (always useful), OS X Mountain Lion, OS X Mountain Lion Server and OS X Lion. Each OS X environment is configured exactly as I need them to, with a snapshot taken after each software update. They all have the required settings and desktop background for me to record any screencast or install any software in. If any software updates are needed, I run them and then replace the old snapshots with a new one.

My current snapshots for my virtualised OS X Mountain Lion environment

Once I’m finished, I just go back to the starting point by reverting to my latest snapshot, and it’s like I never used it.

Whether you’re reviewing software, providing training or just want a sandbox to play in, having a virtualised environment is a great way to achieve this. You’ll often find either Parallels or VMWare Fusion in these Mac software bundles such as MacHeist and both can install OS X from either the recovery partition of your Mac or through the downloaded installer from the Mac App Store.