Previously I posted how I found Invirtus' VM Optimizer (VMO) product to be a big help with virtual machines in the sense that it made them run much faster and, more importantly, shank the overall physical size of the virtual hard disks. The only thing: I never really understood what it was doing.
Recently VMO v2.5 was released as an upgrade from the original 2.0 version. This new version introduces a settings utility that not only lists all the things it does to reduce the size and speed up a virtual machine, but it also has a few configurable options.
For example, one of the things you can let VMO v2.5 do is eliminate the page file on a VHD. While this will obviously degrade performance, if you're trying to get the smallest virtual hard disk possible, this is a nice little feature (you can always recreate a page file after the VM boots sometime in the future). You can also have VMO automatically run disk defragmentation and it's InvirtusFreeSpace.exe utility which zeros out all the free space for a more effective disk compaction (similar to what the VPC pre-compactor does).
Still a slick tool... just shrunk a VHD from 8,583MB to 4,922MB... a 40+% reduction! Great product... it just does exactly what it says it does!