The persistent disk (PD) types of Compute Engine virtual
machines.
Values:
PERSISTENT_DISK_TYPE_UNSPECIFIED (0):
Unspecified (default value).
Selecting this value allows the system to use
any disk type according to reported usage. This
a good value to start with.
PERSISTENT_DISK_TYPE_STANDARD (1):
Standard HDD Persistent Disk.
PERSISTENT_DISK_TYPE_BALANCED (2):
Balanced Persistent Disk.
PERSISTENT_DISK_TYPE_SSD (3):
SSD Persistent Disk.
