The architecture of storage virtualization as

Storage virtualization is the process of presenting a logical view of the physicalstorage resources to a host.

This logical storage appears and behaves as physical storage directly connected to the host.

Someexamples of storage virtualization are host-based volume management, LUN creation, tape storage virtualization, and disk addressing (CHS to LBA).

Benefits:

Increased storage utilization,adding or deleting storage without affecting an application’s availability, and nondisruptive data migration (access to files and storage while migrations are in progress).

At the top are four servers, each of which has one virtual volume assigned, which is currently in use by an application.

These virtual volumes are mapped to the actual storage in the arrays, as shown at the bottom of the figure.

When I/O is sent to a virtual volume, it is redirected through the virtualization at the storage network layer to the mapped physical array.

Challenges / Limitations to implementation of storage virtualization

Scalability:

After virtualization, a storage array can no longer be viewed as an individual entity

As a result, the infrastructure that is implemented both at a physical level and from a virtualization perspective must be able to adequately handle the workload, which may consist of different types of processing and traffic distribution.

Functionality:

In a virtualized environment, the virtual device must provide the same or better functionality than what is currently available on the storage array, and it must continue to leverage existing functionality on the arrays.

It should protect the existing investments in processes, skills, training, and human resources

Manageability:

The management of the storage infrastructure in a virtualized environment is an important consideration for storage administrators.

Introducing a virtualization device breaks the end-to-end view into three distinct domains: the server to the virtualization device, the virtualization device to the physical storage, and the virtualization device itself.

The virtualized storage environment must be capable of meeting these challenges and must integrate with existing management tools to enable management of an end-to end virtualized environment.

Support:

Virtualization is not a stand-alone technology but something that has to work within an existing environment.

This environment may include multiple vendor technologies, such as switch and storage arrays, adding to complexity.

Addressing such complexities often requires multiple management tools and introduces interoperability issues.

Addressing such complexities often requires multiple management tools and introduces interoperability issues.