I use VirtualBox on my Mac to have other operating systems at my disposal. One of my appliances contains a copy of Windows 7 with a fixed, 25GB disk. I’ve run out space and was looking for an easy way to increase it.
I came across the modifyhd command, which in theory let’s you increase the disk space, but it only works on dynamic disks. I opted for performance (fixed disk) when I set up the appliance, and this minor inconvenience is the price.
There are several tutorials out there, but many of them require third-party applications, either on the Mac or in Windows side. The thing is, even without those utilities, it’s fairly easy to increase your disk space.
What we’ll do is create a bigger disk, clone the contents from the small disk to the big disk, and then increase our Windows partition.