# If you’re told there is insufficient free space

VMOptimizer works by creating a new virtual disk and to do so, there needs to be sufficient space on the disk to create the new virtual disk. When finished, the old virtual disk will be moved to the Trash and you can then recover free space by emptying the Trash.

There are two different problems that you can see regarding free space.

The first is the case where you simply do not have enough free space on your disk. If you have any unwanted files on your disk, you can try removing those but don’t forget to empty the Trash as otherwise VMOptimizer cannot use the space.

## Contiguous Free Space

The other case is when there is insufficient contiguous free space. This is subtly different. VMOptimizer places the new virtual disk at a location where it can be in a single chunk, i.e. it should not be fragmented at all. Sometimes, in order to achieive this result, it has to move other files out of the way. Unfortunately, VMOptimizer cannot move all files; system files and files that are currently in use cannot be moved so whilst you might have enough free space on your system, there are too many files that VMOptimizer cannot move preventing VMOptimizer from working.

## Try these solutions:

- Try emptying the Trash.
- Try removing any unwanted files that you might have and make sure you empty the Trash afterwards.
- Terminate all other applications to reduce the number of files that cannot be moved.
- If your system files are particularly fragmented, you can try using a dedicated defragmentation tool such as iDefrag. You can use iDefrag’s free demonstration version to see whether you have a lot of system file fragmentation.