Whether you’re using Windows or a Mac, if you’re thinking about using virtualization for the first time on your laptop to test out new operating systems like Windows 7 or Windows 2008 R2, there’s a few things you should know.
Get Another Hard Drive
Laptop drives aren’t quick to begin with, and running two operating systems simultaneously doesn’t make life any easier for your pokey drive.
Your laptop probably has a removable CD/DVD drive, and that drive bay slot is designed to hold more than just optical drives. You can pick up a hard drive caddy that slides into that same slot. Check your laptop’s hardware manual for the exact part number, and then search Ebay for that part number. Drive bay caddies are usually available for around $20-$40.
Apple Macbook users can swap out their internal drives with the MCE OptiBay drive adapter too. This voids the daylights out of your warranty, but it’s not as hard as it looks. I just went through this process with my own Macbook Pro, and I recommend it highly – I have a review of that coming soon.
Pay close attention to the caddy bay specs, and then order a hard drive to match. Most laptop bay caddies take either a PATA or SATA 2.5″ laptop drive. Some high-capacity 2.5″ hard drives are a non-standard 12.5mm high instead of 9mm, so make sure you don’t get a drive that’s too thick to fit inside your caddy. Buy the fastest (not the largest) drive you can afford. I use the 2.5″ performance test charts at TomsHardware for reference, and the current king-of-the-hill on performance per watt is the Seagate Momentus 5400.6 for around $90.
If your laptop doesn’t have a drive bay adapter or if you’re not willing to give up that trusty CD/DVD drive, you can also use an external USB hard drive. Just make sure to get one of the 2.5″ models that doesn’t require external power – the less cables you have to carry, the better. Then mount it on the back of your laptop display using Velcro tape. Presto, you can detach it and reattach it whenever you need to pack the laptop into a tight case.
After installation, Windows will see this as just another hard drive that you can partition and format. When you build virtual machines, store them on this secondary hard drive. Bonus points for backing up your important files there, too.
Get As Much Memory As Possible
The more memory you have, the better. I’d consider 4gb the minimum to comfortably run two Windows OS’s simultaneously no matter what virtualization software you’re using.
To find out how much memory your laptop can handle, use the memory configuration tool at Crucial.com.
When It Comes to Virtual CPUs, Less Is More
When building your guest OS’s, always set them up with just one CPU. Virtualization CPU scheduling has a gotcha: if your virtual OS is set up with two CPUs, then the hypervisor’s scheduler will wait until two cores are available before doing any work in the guest – even if the guest only needs to do one core’s worth of work. This same concept holds true at the server-level too – don’t set up your ESX guests with 4 CPUs just because you can.
Understand Virtual Networking Modes
The various flavors of hypervisors have three basic network modes for guests:
- Bridged Networking – aka Home Office Mode. This is the one you’re going to think you want, because each virtual machine gets its own TCP/IP address directly from your home router just like your host machine does.
- Network Address Translation – aka Starbucks Mode. The hypervisor acts as a little router, and it assigns unique TCP/IP addresses to each guest. The guests aren’t on the public network directly, but they can access network resources just fine. This is my favorite because I can switch back and forth between different networks without the guest servers wigging out. I can suspend them to disk at home, then wake them up at Starbucks and nothing changes. I highly recommend this mode, especially since it’s easy to switch back and forth between this and…
- Host-Only Networking – aka Tin Foil Hat Mode. Like Starbucks Mode, each guest gets its own internal TCP/IP address on your laptop’s private network, but there’s no communication with the outside. This is good for testing software that might have conflicts with other stuff on your network, and it’s also good when you’re on a slow network. When I’m using my aircard and I don’t have a good signal, I’ll boot up my guests in Host-Only mode so that they don’t try to connect to Microsoft to download updates or anything else that might suck up my precious bandwidth.
Back Up Your Virtual Hard Drives
Installing the Windows guest, configuring it the way you want it, and patching it takes hours. After you’re done – but before you install any third party software – shut it down and copy the flat files to another directory.
When you want to spin up a new virtual server, just make another copy of those flat files and import them into your hypervisor. The methods are slightly different depending on what virtualization software you’re using, but all of them are much easier than reinstalling Windows from scratch and patching it.
That’s it for my tips – if you’ve got more to share, feel free to leave ’em in the comments for other folks to get started easier.
Oh, And the Contest! Want a Free 120GB 2.5″ USB Drive?
I’m moving to Chicago soon, and I need your help. I need to clean out my home office, but I hate throwing gadgets away. Time to give away some of my extra goodies.
Today, since we’re talkin’ USB drives, let’s give those away. I’ve got two self-powered USB 2.5″ hard drives, both 120 gigs, both exceedingly stylish. One is a speaker’s gift from the PASS Summit last year, and one is a leather-bound hard drive. (I have very strange tastes in USB devices.)
To win, just leave a comment here. Only one comment per person, please. I’ll draw two comments at random on Saturday Sept 12th at 7AM EST and announce ’em here. Good luck!