Some screenshots from Windows Server Technical Preview: The Server Version That Does Not Yet Have A Number.
When adding disks to a VM in vSphere you may have seen “Disk Provisioning type” and wondered what the benefits of each type were. Disk performance and disk space used are what governs the decision to use each type.
The 3 disk provisioning types are “Thick Provision Lazy Zeroed”, “Thick Provision Eager Zeroed”, “Thin Provision”. The things I want to explain are the difference between “thick” and “thin” disk and the difference between “eager” and “lazy” zeroing.