in Future Howard, Virtualisation

VHD Size

Again, a techy post more for my future self’s benefit (so little space in my memory for anything useful, it being full of StarTrek trivia and the like). A trick to optimise a VHD (Microsoft’s Virtual Harddrive format – used in Virtual PC and Virtual Server). Turn of the system file checker. Not always advisable, but if you’ve created a machine where you think you don’t need it, try this.
To turn off SFC, open a command prompt and run

sfc /cachesize=0
sfc /purgecache

Then perform the standard compaction routine in Virtual PC/Virtual Server. For even more benefit, see also the Invirtus Optimizer which is outstanding, taking a 4.2GB VHD down to 1.4 by removing the cruft it didn’t need.