A database administrator has requested a disk for a virtual machine that will run an I/O intensive
database application on an ESXi 5.x host.
Which two disk types will best fit the needs of the application? (Choose two.)
A.
Raw Device Mapped Disk
B.
Thin Provisioned Disk
C.
Thick Provision Lazy Zeroed Disk
D.
Thick Provision Eager Zeroed Disk
C: Wrong
D : Correct
A : Correct
In my opinion.
http://www.vmware.com/pdf/Perf_Best_Practices_vSphere5.0.pdf
Lazy-zeroed – A lazy-zeroed thick disk has all space allocated at the time of creation, but each
block is zeroed only on first write. This results in a shorter creation time, but reduced
performance the first time a block is written to. Subsequent writes, however, have the same
performance as on eager-zeroed thick disks.
Thin – Space required for a thin-provisioned virtual disk is allocated and zeroed upon first write, as opposed to upon creation. There is a higher I/O cost (similar to that of lazy-zeroed thick disks) during the first write to an unwritten file block, but on subsequent writes thin-provisioned disks have the same performance as eager-zeroed thick disks.
I agree, Eager Zero would require more resources up front during creation, but would perform best for I/O intesive applications once created. RDM seems self explanatory in this case.
Thin and Lazy Zero would take less time to setup but would be slow in the initial writes during ever day operations until enough blocks are written to cover the space utilization of the DB. Thus slowing the DB I/O operations.
A+D seems better to me as well.
A & D are the best choices.
A+D
A D
A & D is correct