An administrator is deploying a number of virtual machines to an NFS datastore. The NFS datastore does not support hardware Acceleration.
Which virtual disk type is supported on this platform?
A.
Flat disk
B.
Raw Device Mapped disk
C.
Thin Provisioned disk
D.
Thick Provisioned disk
Explanation:
Reference: http://vinfrastructure.it/en/2011/08/vcp5-exam-prep-part-3-1/NFS Disk Formats
The only disk formats you can use for NFS are thin, thick, zeroedthick and 2gbsparse.
Thick, zeroedthick and thin formats usually behave the same because the NFS server and not the ESXi host determines the allocation policy. The default allocation policy on most NFS servers is thin. However, on NFS servers that support Storage APIs – Array Integration, you can create virtual disks in zeroedthick format. The reserve space operation enables NFS servers to allocate and guarantee space.
Why it D wrong?
Or, is the question asking about the default policy?
I think because the question says “The datastore does not support hardware acceleration” i.e. “VAAI” Thick provsioned is not an option. However, the fact that the answerer says “The default allocatoin policy on most NFS servers is thin” is poor justification. “Most” is not all inclusive. Therefore, if even one NFS server has the default storage allocation as Thick the answer is either C or D. IMO
On NFS datastores that do not support Hardware Acceleration, only thin format is available.
http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.vm_admin.doc_50%2FGUID-4C0F4D73-82F2-4B81-8AA7-1DD752A8A5AC.html