In the Hard Disk pane, you can view and configure the virtual machine's hard disk-related settings.
To open these settings, choose Actions > Configure > Hardware, then click Hard Disk.
Source
Use this field to specify the virtual hard disk file (.hdd) that emulates the virtual machine hard disk:
To use the Boot Camp partition, select it from the list.
To use a virtual hard disk file, choose it from the list, or click Choose an image file and specify the path to the desired image file (.hdd).
Properties
Click this button to edit the hard disk size.
Location
Use this field to specify the type of interface for connecting the hard disk. This option is for advanced users only.
Enable TRIM
In most cases, the space that the virtual machine takes up on your hard disk expands as you add files and other data but isn't reduced when you delete data. To set Parallels Desktop to automatically reduce disk space, select Enable TRIM. This option may affect the performance of HDD (but not SSD) disks.
