Virtual Disk Manager (vmware-vdiskmanager) is a Fusion utility that you can use to create, manage, and modify virtual disk files from the command line or in scripts.

Virtual Disk Manager is included when Fusion is installed. With Virtual Disk Manager, you can enlarge a virtual disk so that its maximum capacity is larger than it was when you created it. This feature is useful if you need more disk space in a given virtual machine, but do not want to add another virtual disk or use ghosting software to transfer the data on a virtual disk to a larger virtual disk.

You can also use Virtual Disk Manager to change how disk space is allocated for a virtual hard disk. You can preallocate all the disk space in advance or configure the disk to grow as more disk space is needed. If you allocate all the disk space but later need to reclaim some hard disk space on the host system, you can convert the preallocated virtual disk into a growable disk. The new virtual disk is still large enough to contain all the data in the original virtual hard disk. You can also change whether the virtual hard disk is stored in a single file or split into 2GB files.

The Virtual Disk Manager file, vmware-vdiskmanager, is located in the Applications/VMware Fusion.app/Contents/Library directory.