What should you include in your design?

You plan to deploy a distributed database application that runs on multiple Windows Server 2008 R2 servers.

You need to design a storage strategy that meets the following requirements:

Allocates storage to servers as required

Uses the existing network infrastructure

Uses standard Windows management tools

Ensures that data is available if a single disk fails

What should you include in your design?

A.
An iSCSI disk storage subsystem that supports Microsoft Multipath I/O. Configure the storage subsystem as a RAID?0 array.

B.
An iSCSI disk storage subsystem that supports Virtual Disk Service (VDS). Configure the storage subsystem as a RAID?5 array.

C.
A Fibre Channel (FC) disk storage subsystem that supports Microsoft Multipath I/O. Configure the storage subsystem as a RAID?0 array.

D.
A Fibre Channel (FC) disk storage subsystem that supports the Virtual Disk Service (VDS).
Configure the storage subsystem as a RAID?5 array.

Explanation:
MCITP Self-Paced Training Kit Exam 70-646 Windows Server Administration:

Virtual Disk Service (VDS)
Virtual Disk Service (VDS) provides a standard set of application programming interfaces (APIs) that provide a single interface through which disks can be managed. VDS provides a complete solution for managing storage hardware and disks and enables you to create volumes on those disks. This means that you can use a single tool to manage devices in a mixed storage environment rather than tools provided by different hardware vendors. Before you can manage a LUN using Storage Manager For SANs, you must install its VDS hardware provider. This will usually be provided by the hardware vendor. Prior to purchasing a storage device to be used on your organizations SAN, you should verify that a compatible VDS hardware provider exists.

VDS defines a software and a hardware provider interface. Each of these providers implements a different portion of the VDS API. The software provider is a program that runs on the host and is supported by a kernel-mode driver. Software providers operate on volumes, disks, and partitions. The hardware provider manages the actual storage subsystem. Hardware providers are usually disk array or adapter cards that enable the creation of logical disks for each LUN type. The LUN type that can be configured will depend on the options allowed by the VDS hardware provider. For example, some VDS hardware providers will allow the RAID-5 (Striped with Parity) LUN type to be implemented, while others might be limited to providing the Mirrored or Spanned LUN types.

MORE INFO More on VDS
For more information on the functionality of VDS, consult the following TechNet article:http://technet2.microsoft.com/windowsserver/en/library/dc77e7c7-ae44-4483-878b- 6bc3819e64dc1033.mspx?mfr=true

Storage Manager For SANs
You can use the Storage Manager For SANs console to create LUNs on Fibre Channel and iSCSI storage arrays. You install Storage Manager For SANs as a Windows Server 2008 feature. To use Storage Manager For SANs to manage LUNs, the following criteria must be met:
The storage subsystems that you are going to manage must support VDS.
The VDS hardware provider for each subsystem must already be installed on the Windows Server 2008 computer. When you open Storage Manager For SANs from the Administrative Tools menu, you are presented with three main nodes, which have the following functionality:
LUN ManagementThis node lists all of the LUNs created with Storage Manager For SANs. From this node you can create new LUNs, extend the size of existing LUNs, assign and unassign LUNs, and delete LUNs. You can also use this node to configure the Fibre Channel and iSCSI connections that servers use to access LUNs.
SubsystemsThis node lists all of the storage subsystems currently discovered within the SAN environment. You can rename subsystems using this node.
DrivesThis node lists all of the drives in the storage subsystems discovered in the SAN. You can identify drives that you are working with by making the drive light blink from this node.

You can use any LUN type that is supported by the storage subsystem that you are deploying. The different LUN types are:
SimpleA simple LUN uses either an entire physical drive or a portion of that drive. The failure of a disk in a simple LUN means that all data stored on the LUN is lost.
SpannedA spanned LUN is a simple LUN that spans multiple physical drives. The failure of any one disk in a spanned LUN means that all data stored on the LUN is lost.
StripedData is written across multiple physical disks. This type of LUN, also known as RAID-0 has improved I/O performance because data can be read and written to multiple disks simultaneously, but like a spanned LUN, all data will be lost in the event that one disk in the array fails.
MirroredThis LUN type, also known as RAID-1, is fault tolerant. Identical copies of the LUN are created on two physical drives. All read and write operations occur concurrently on both drives. If one disk fails, the LUN continues to be available on the unaffected disk.
Striped with ParityThis LUN type, also known as RAID-5, offers fault tolerance and improved read performance, although write performance is hampered by parity calculation. This type requires a minimum of three disks and the equivalent of one disks worth of storage is lost to the storage of parity information across the disk set. This LUN type will retain data if one disk is lost, but all data will be lost if two disks in the array fail at the same time. In the event that one disk fails, it should be replaced as quickly as possible.