I am running Leopard, Fusion 1.1 and XP pro as a VM. I have given OS X and the VM each 160GB of hard drive space
When I copy the VM file to do an external backup, it is about 40GB! This seems extremely large for an VM that has only 2Gb or less of data.
I would have expected the whole VM to be less than 10GB.
What is causing the VM file to be so large? Is there anything I can do to get a smaller file so I can burn to a DVD?
If you start off with a sparse disk and write 2GB of data, it takes 2GB. If you add an additional 8 GB, it's 10 GB. But if you then delete 5 GB, it still takes up 10 GB - this is because when most filesystems delete a file, they only delete the metadata, not the actual file. However, we can't tell what is metadata and what is normal data, so the virtual disk remains large until you explicitly shrink it (part of the shrink process helps us figure out what space is actually needed).