Workstation User’s Manual : Using Disks and Disk Drives : Using VMware Virtual Disk Manager

Using VMware Virtual Disk Manager
VMware Virtual Disk Manager is a Workstation utility that allows you to create, manage, and modify virtual disk files from the command line or in scripts.
You can enlarge a virtual disk so that its maximum capacity is larger than it was when you created it. This 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 cannot do this with physical hard drives.
You can also change disk types. When you create a virtual machine, you specify how disk space is allocated, as follows:
Space allocated for the virtual disk begins small and grows as needed. This corresponds to the growable disk type for Virtual Disk Manager.
If you allocate all the disk space for a virtual disk but later need to reclaim some hard disk space on the host, 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 disk.
You can also change whether the virtual disk is stored in a single file or split into 2GB files.
These features and the ability to use scripting to automate management of virtual disks were added to Workstation in version 5.0. See the VMware technical note about using Virtual Disk Manager.