The second of virtualized storage configuration would have a storage processor in between the storage consumers and the disk resources. This storage processor virtualizes the storage resources with a mapping table. Products in this space include the IBM SAN Volume Controller. This architecture is shown in this figure:
The third configuration introduces a split-path approach to presenting storage resources to consumers. The key is application integration to the switches to manage the path assignment (sometimes referred to as controlled path) from the switches to the storage resources.
Products in this approach include EMCs Invista storage virtualization. The figure below shows this architecture:
In each of the architectures, there may be multiple switches shown. This is to show the path flow rather than the pieces and parts in place. For most switches, zones can be assigned to provide a logical area for the path to flow without adding an entirely separate switch infrastructure, if the security requirements would permit that type of separation.
What options are available for virtualized storage beyond traditional storage?
With the three principle types of storage identified above, there are still other products available for administrators to select from. This includes options that are software-only and that use commodity hardware in favor of the generally higher-cost options from the traditional storage companies.
Rick Vanover, vExpert, VCP, MCITP, MCTS, MCSA, is an IT Infrastructure Manager for Alliance Data in Columbus, Ohio. He is an IT veteran specializing in virtualization, server hardware, operating system support and technology management. Follow Rick on Twitter at @RickVanover .