Virtualization is one of the hottest technologies today and all major product vendors offer a variety of solutions that are applicable in different areas. One of the key areas in this domain is data center virtualization, whose vital component is storage virtualization.Storage
Requires Free Membership to View
virtualization presents a logical view of physical storage resources to
the hosts. The advantages are many
when it comes to storage virtualization. These include non-disruptive data migration, increased
storage utilization and storage consolidation as also the ability to implement information life
cycle management (ILM) using your current storage infrastructure. There are basically two choices for
storage virtualization — block level storage virtualization or file level storage
virtualization. By talking about the former option for storage virtualization, we refer to storage
area network (SAN) virtualization. While considering the latter option for storage virtualization,
we refer to network attached storage (NAS) virtualization. While storage virtualization brings in
many benefits, there are some challenges as well that the storage
virtualization solution has to address. These include scalability, functionality, manageability
and support.
• Scalability
An environment which lacks storage virtualization will have islands of storage (or storage systems)
from the same or different vendors. Each storage system caters to requirements of various
applications individually as well as in terms of IOPS (Input/output operations per second) and
capacity. But after the storage environment is virtualized, it is not possible to individually
address storage systems. Instead, the whole environment should be analyzed. Moreover, the
implemented and virtualized infrastructure has to be capable of handling individual requirements of
applications that it caters to. Hence, while conduction evaluation
exercises for storage virtualization solutions, care needs to be taken that they are designed
keeping in mind future storage requirements.
• Functionality
Since an environment for storage virtualization will have storage from different vendors or the
same vendor, each system will have advanced functionality. Hence, the storage virtualization
solution must provide the same functionalities as well as continue to leverage the arrays' existing
functionality.
• Manageability
Introduction of virtualization in the storage infrastructure divides the end-to-end view in to
three distinct views—server to virtualization device; virtualization device to physical storage;
and the virtualization appliance itself. Storage virtualization should address manageability of
distinct views as well as integrate with existing management tools to enable end to end management
of the virtualized environment. Foreffective
storage virtualization, the solution should not bring with it unnecessary complexities to the
current storage infrastructure, as that will make manageability difficult.
• Support
When it comes to support, we can consolidate products from a single vendor when there is no
virtualization. But for storage
virtualization implementations, the storage systems are of different models and procured from
various vendors. Hence, the virtual solution needs to be well evaluated so that it addresses
interoperability issues for storage virtualization success.
• Availability
The whole storage environment is in control of the storage virtualization solution whose failure
will lead to downtime of SAN infrastructure—causing inaccessibility of storage to hosts. So the storage
virtualization solution should be fault-tolerant and robust with five nines of availability
(99.999).
• Performance
Different storage systems are capable of handling a predefined work load for storage
virtualization. Hence the solution should be designed in such a way that the resources are utilized
optimally, and that the applications are not starved of resources. Further, for storage
virtualization efficiency, it's critical that the solution does not become a bottleneck and
hamper application performance.
• Monitoring and reporting
Most solutions for storage virtualization available in the market lack monitoring and reporting
capabilities. So for effective
storage virtualization, the solution should integrate with existing monitoring and reporting
infrastructure. This in turn will ensure that resource and storage utilization can be regularly
monitored and reported to analyze the pattern of business activity.
About the author: Anuj Sharma is an EMC Certified and NetApp accredited professional.
Sharma has experience in handling implementation projects related to SAN, NAS and BURA. He also has
to his credit, several research papers published globally on SAN and BURA technologies.
This was first published in August 2010