Introduction to Virtualization
If you select the checkbox Allocate All Disk Space Now,
VMware will create a virtual hard disk file that is the size you selected.
Otherwise, VMware will automatically expand the virtual hard disk file's
size as the space is used. The trade-off is that if you choose to allocate the
space immediately, the virtual hard disk may consume much more space
on the host system's hard disk than it is actually using. On the other hand,
if the space is allocated immediately, then the performance of creating
files or writing new blocks to the disk will be much faster, because the
space is already allocated. I recommend leaving this checkbox unchecked,
but choosing a size that is comfortably larger than you think you need.
This way, you efficiently use actual hard disk space, and the automatic
expansion process is generally not a huge price to pay for most uses.
Independent disk mode
This option allows you to configure a virtual
hard disk as independent of any snapshots you make of the virtual
machine. Note that you can have multiple virtual hard disks in each
virtual machine, and for some applications, you may want the one or more
of the virtual hard disks to not be part of the VMware snapshot process.
Generally, you will leave this option unselected.
Setting virtual hard disk properties
377 Chapter 23: Introduction to Virtualization File options If you select the checkbox Allocate All Disk Space Now, VMware will create a virtual hard disk file that is the size you selected.