Having a good understanding of the problem that needs to be solved and how a particular technology might be applied to address that problem is essential. Despite the issues that I alluded to previously, there are several bright spots in storage virtualization offerings that seem to be resonating and are being deployed to address specific storage management challenges. Here are two examples from mainstream vendors:
Tiered storage: Many organizations excitedly adopted tiered-storage strategies only to become frustrated by additional management complexities that have hindered expected financial benefits. The challenges of diverse management tools and data migration among tiers are two areas where virtualization can help. One interesting approach is the controller-centric Universal Storage Platform (USP) from Hitachi Data Systems (HDS). The key here is that virtualization has existed for years at the storage controller layer within the array enclosure and is well-understood. HDS simply extended their controller capabilities to support additional types of arrays beyond the frame boundary. It is now possible to leverage the identical sets of services such as split mirrors and replication among all tiers in a consistent manner behind the same controllers.
File system aggregation: Network-attached storage (NAS) is a technology that has been wildly successful, in some cases, too successful. While people love the ease of setting up and managing NAS appliances, in large shops the number of appliances has created its own management challenges. Issues like laying out shares effectively, migrating among boxes for load balancing, capacity management, and technology refreshes can be complex and time-consuming. The complexity can be reduced through virtualized global namespace technology to aggregate and present a common file system view. Companies such as Brocade Communications Systems with its NuView acquisition and Network Appliance with its Virtual File Manager (OEM'd from NuView) isolate the logical file system structure from its physical layout to simplify these management chores.
As storage virtualization continues to evolve, the number of technology options will inevitably grow. Storage managers must continue to be selective in applying technologies that clearly reduce complexity and address problems.
Jim Damoulakis is chief technology officer of GlassHouse Technologies Inc., a leading provider of independent storage services. He can be reached at jimd@glasshouse.com