Values:
BACKING_TYPE_UNSPECIFIED (0):
Default value.
BACKING_TYPE_FLAT_V1 (1):
Flat v1.
BACKING_TYPE_FLAT_V2 (2):
Flat v2.
BACKING_TYPE_PMEM (3):
Persistent memory, also known as Non-Volatile
Memory (NVM).
BACKING_TYPE_RDM_V1 (4):
Raw Disk Memory v1.
BACKING_TYPE_RDM_V2 (5):
Raw Disk Memory v2.
BACKING_TYPE_SESPARSE (6):
SEsparse is a snapshot format introduced in
vSphere 5.5 for large disks.
BACKING_TYPE_SESPARSE_V1 (7):
SEsparse v1.
BACKING_TYPE_SESPARSE_V2 (8):
SEsparse v1.
