2.2.2.18.1.1 CREATE_VIRTUAL_DISK_FLAG

The CREATE_VIRTUAL_DISK_FLAG enumeration defines the properties of a virtual disk that is being created.

 typedef enum _CREATE_VIRTUAL_DISK_FLAG
 {
   CREATE_VIRTUAL_DISK_FLAG_NONE = 0x0,
   CREATE_VIRTUAL_DISK_FLAG_FULL_PHYSICAL_ALLOCATION = 0x1
 } CREATE_VIRTUAL_DISK_FLAG;

CREATE_VIRTUAL_DISK_FLAG_NONE:  Indicates to the server that no flags have been specified. CREATE_VIRTUAL_DISK_FLAG_NONE specifies that a virtual disk file will be allocated as the backing store for the virtual disk and that this file will automatically increase in size to accommodate the allocated data.

A virtual disk created using the CREATE_ VIRTUAL_DISK_FLAG_NONE flag has a virtual disk file backing store that at any given time is as large as the actual data written to it, plus the size of the header and footer. As more data is written, the virtual disk file automatically increases in size.

For example, if the CREATE_VIRTUAL_DISK_FLAG_NONE flag is used to create a virtual disk that is 2 gigabytes in size, the initial size of the virtual disk file backing store can only be 2 megabytes. As data is written to this disk, the virtual disk file backing store increases in size, with a maximum size of 2 gigabytes.

CREATE_VIRTUAL_DISK_FLAG_FULL_PHYSICAL_ALLOCATION:  Specifies that the server preallocates all physical space necessary for the virtual size of the virtual disk. A fixed size virtual disk file will be allocated as the backing store for the virtual disk. For example, creating a fixed size virtual disk that is 2 gigabytes in size using this flag will result in a virtual disk file that is approximately 2 gigabytes in size.