Editor's Note: Following is the first in a series of tips about storage virtualization taken from a white paper by Robert Nieboer of StorageTek. This document is fequently requested by searchStorage discussion forum users.
Virtualization: What are you getting for your money? (Part 1)
By Robert Nieboer
The word ?virtualization? has crept into the IT lexicon. What does it mean and how much of the claims are hype versus delivering real value to the business?
Virtualization separates the presentation of storage to the server operating system from the actual physical devices. Neither of these statements implies an underlying architecture, yet most claims to storage virtualization today are made in the context of storage networks. This is no accident, since storage networking and storage virtualization are trying to address the same fundamental problem ? storage manageability. In fact, it would be fair to say that, even as storage networking is only just beginning to be widely implemented, it is already recognized that we need to do something more to ease the storage management burden.
We believe that the scale of the problem is so large, that the goal of all the efforts surrounding storage and storage manageability should be to plan for the elimination of human intervention in storage management. Virtualization is a step in that direction, and we believe that automated policy-based management algorithms and
Most virtualization implementations are concerned with simplifying the management of large storage infrastructures shared across multiple heterogeneous servers and applications. Presenting a logical view of storage devices to servers that is disassociated from the physical reality can have the effect of hiding complexity, masking change and improving people productivity. What is missing from most virtualization implementations is the means to reduce the amount of storage infrastructure needed to satisfy application storage requirements. Yes, manageability is a serious issue that requires resolution. But so is infrastructure cost.
Users should carefully examine the claims of vendors about their storage virtualization products. What is available today? How open is it? Is policy-based management and intelligence present or planned? Is infrastructure cost reduction an objective?
Storage virtualization is necessary to overcome some of the interoperability limitations of
storage networking, as well as in its own right for providing two huge and timely benefits to IT
1. Significantly improved storage manageability
2. Significantly reduced storage infrastructure cost
The first benefit is the objective of all of the virtualization architectures and implementations. However, the second is only obtained in two cases:
- if virtualization is implemented at the device level, and if the virtualization engine is
designed to exploit the fact that both the logical devices and the physical devices exist within
the same span-of-control and so optimize the use of physical capacity.
- and/or if virtualization is implemented in such a way as to transparently exploit the cost-benefits of a policy-driven multi-level storage hierarchy.
Storage virtualization is an important development. Right now, treat vendor claims with a degree of skepticism until functionality and roadmaps are understood.
* To view this white paper in its entirety, click on http://searchstorage.techtarget.com/originalContent/0,289142,sid5_gci768691,00.html.
* Check out the searchStorage Featured Topic on Virtualization for more resources, news, and expert advice.
* Browse links to other virtualization resources in our Best Web Links .
About the author: Rob Nieboer is a corporate evangelist for StorageTek , and is currently responsible for global industry
analyst relations for the company. Rob's background includes some 34 years as an IT practitioner,
with the last 17 years focused on storage. His career with StorageTek has included responsibilities
for systems engineering, systems engineering management, worldwide tape and library marketing,
regional marketing, and strategy.
This was first published in September 2001