How to really compact Virtual PC hard drives

  • November 18, 2008
  • James Skemp
  • software

No names mentioned, but I've recently been using a number of virtual machines for testing purposes.

One machine has Internet Explorer 6 and Firefox 2 installed, while a second has Internet Explorer 7, Firefox 3, and the most recent versions of Opera, Safari (for Windows) and Chrome.

However, the virtual hard drives were 10 GB each, due to a large number of apps being installed that didn't need to be, for our browser-based testing.


Even after uninstalling all of the unnecssary applications, and no matter how much compacting I did, they just didn't seem to want to shrink.

And then I started looking at using difference disks and found this great post by Andrew Connell, titled HOWTO: Use Virtual PC's Differencing Disks to your Advantage.

Before I start creating differencing disks, I want to optimize these two images. 


After performing the steps Andrew lays out I'm down to under 5 gig each. Now that's some savings.

As an aside, I ran a defrag on my work computer as well, since I'm positive one hasn't been run in well over a year (I don't recall when I got it, which also is when it was bought, but it's been that long). If I thought the amount of space I saved after the compacting worked I was very wrong. Unfortunately, even after running Contig I'm still extremely fragmented, but even with 20+ gigs free it just can't defrag any further ...

How's your work/home machine looking?