ACME Tools has a vSphere 5.x deployment with an older iSCSI storage array. The administrator is considering adding an additional array which will include support for the vStorage APIs for Array Integration (VAAI).
Which two tasks would would be completed in a reduced period of time if the new array was added? (Choose two.)
A.
creating VMFS datastores on the new array
B.
creating fault tolerant virtual machines on the new array
C.
migrating virtual machines using Storage vMotion between the arrays
D.
writes to thin provisioned virtual disks on the new array
not sure why B is correct answer, because it reduce the time to create the sec copy thanks to hardware acc?
B is correct because it says “creating fault tolerant VMs” not “enabling FT on an existing VM”. VAAI would speed up the creation of a VM that you planned on enabling FT for. Poorly-worded question for sure.
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1021976
B is correct because VAAI uses this fundamental operation:
• Clone Blocks/Full Copy/XCOPY, which is used to copy or migrate data within the same physical array
D is correct because VAAI uses this fundamental operation:
• Thin Provisioning in ESXi 5.x and later hosts, which allows the ESXi host to tell the array when the space previously occupied by a virtual machine (whether it be deleted or migrated to another datastore) can be reclaimed on thin provisioned LUNs.
one more site for reading
http://www.zdnet.com/vsphere-5-vaai-and-the-death-of-the-storage-array-4010024253/
Why is C wrong ?
vSphere text p375 says Storage vMotion is much faster by VAAI.
because it says “between the arrays”. Which seems to indicate that the Storage vMotion would occur between the old array without VAAI and the new one with VAAI. In which case the operation would not be any faster.
However, B and D are both answers that would be faster on an array with VAAI enabled and only utilize the new array.
I think that the correct answers are B & C. The reason D is incorrect is that thin provisioned virtual disks are NOT the same thing as thin provisioned LUNs on an array.
VAAI improves space reclamation on thin provisioned LUNs, not thin provisioned vDisks.
Besides writes to thin provisioned vDisks expand the size of the vDisks, so reclamation is definitely not going to happen.