Pros and Cons of Storage Virtualization
by Hu Yoshida on Aug 29, 2008
Charlie Schluting posted a recent article on serverwatch.com , where he explains “Storage Virtualization for Network Administrators” and refers to block and file virtualization. In this article he also talks about the pros and cons of storage virtualization.
The largest benefits he cites are:
· Non disruptive data migration
· Centralized management
· Increased utilization
· Better visibility
I would certainly agree with this list and would add a few more:
· Consolidation through non disruptive movement of data from under utilized or older storage frames
· Higher availability through non disruptive movement or replication of data for offline processing and maintenance
· Service Level Management through the allocation of virtual storage resources
· Improved performance if virtualization controller has a larger faster cache, and faster port processors.
· Improved security if the virtualization controller can support logical partitioning, FC-SP authentication, Role Based Access, Audit logging, and other security features
· A Service Oriented Architecture approach to storage which enables functions in the virtualizations controller to be applied to storage capacity from lower level storage systems..
On the con side he raise concerns about the over commitment of the virtualization controller and advises on the need for “an extremely fast, redundant and memory-rich device”. That is a recommendation which leaves out most virtualization appliances and switches. However, an enterprise storage controller like the USP V/VM can fill this requirement.
He also notes that Information Life Cycle Management, the ability, as he describes it, to automatically migrate less frequently accessed data to less expensive storages is limited to a file or LUN basis where some data may be important and some may not. Information or data life cycle management has many definitions, but the best way to address this is with an active archive, like HCAP, which ingests, indexes, manages, and searches data on an object or content basis. HCAP also can us the USP V and leverage services in the USP like dynamic (thin) provisioning, and replication services.
I certainly agree with Charlie that the pros of storage virtualization outweigh the cons and will change the way storage is managed so that storage administrators can focus on the overall site scalability and performance.
Thank you! I certainly agree with your additions (specifically service level management).