Determine appropriate RAID level for various Virtual Machine workloads

When you determine the volume layout, you evaluate the type of data to be stored and the number of volumes that you want to create.  Each logical drive should be on a separate volume, for easy future expansion if needed and better performance.


Typically with the operating system and application data, you would use a RAID 5 volume.  For things like transaction logs or volumes requiring a high volume of changes, you should use a RAID 1 or RAID 1+0 volume.

Physical Design Diagram

The third design diagram is the physical design diagram.  THis diagram will list specific hardware and vendors; along with CPU, memory, storage, PCI cards, configurations and LUN assignments.  This design is typically more than one diagram but usually more like a series of diagrams.  Below is an example of a physical design.


Logical Design

After you create a conceptual design, you next need to create a logical design diagram.  This diagram is a lower-level design showing the relationship of the hosts, storage and networks; and how they interact with each other.  All devices are listed as generic containers, specific hardware, CPUs, memory, LUNs and so on are NOT listed in the logical design.  Below is an example of a logical design diagram.


Conceptual Design

The conceptual design is a high-level graphical depiction of based on information gathered during the analysis and from the key stakeholders.  You want to be able to answer as many questions with this design document as possible, making sure that all goals and requirements outlined are answered.  The following image is a very basic conceptual design, but notice we do not mention hardware, storage, or network.  I can not stress enough that this is a high-level depiction of what the configuration will look like when completed.


VMware Design Methodology

The design methodology is broken down into three (or four) phases:

First is the architectural vision. During this phase you will define the scope, assign goals, list requirements, state assumptions, define constraints and outline the risks.  This phase will server a the roadmap for the remainder of the project.

The next phase is the architectural analysis, which we actually take a more in-depth view of the existing infrastructure.  Gather and analyze information on existing network, servers and storage.  Documenting detailed information on all these pieces is key because this information will be needed later on.

The third phase is the technology architecture, where we take all the information from the previous phase and use it to create a conceptual design, a logical design and a physical design.

There can be a migration planning phase as a fourth phase, but I usually like to think of this as a separate project.  With this phase, the information gathered in phase is valuable for their migration from physical to virtual.  This information should include the processor, memory and disk utilizations.