User`s guide

Configuring the Virtual Machine 178
If you use an expanding (p. 217) virtual hard disk in your virtual machine, its image file size on
the physical hard disk increases as you add new data to the virtual hard disk. When you delete
some data from this virtual hard disk, free unused space appears on the disk but the amount of
space your virtual machine occupies on the hard disk of your Mac does not reduce. To regularly
free the unused space back to Mac, use the Automatically compress virtual disks option. The
virtual hard disk in an expanding format will be reviewed twice a day and, if the unused space
occupies more than 50 percent of the hard disk image size, it will be compressed and the hard
disk image file size will be decreased. As a result, there will be more free space on your Mac
hard disk.
Note: Compressing can be performed for virtual machines without snapshots (p. 134) and with
the Undo disks option (p. 179) disabled.
In the Hard Disk pane (p. 202), you can compress the disk manually whenever you want.
If you want to prevent Virtual Machine Configuration from unauthorized changes, click the
Lock icon
at the bottom of the window. The next time someone wants to change the
settings in any pane of Virtual Machine Configuration, an administrator's password will be
required.