Network file virtualization

Computer Technology Review, Nov, 2004 by John Schroeder

Virtualization is key to managing today's demanding file storage requirements. One of the most promising--and challenging--developments is network file virtualization (NFV) that enables unstructured data management without disrupting end-user or application access. Done correctly, network file virtualization optimizes networked attached storage (NAS), eases storage management overhead, simplifies end-user access, and enables additional storage management functionality.

Strategic approaches like ILM. Storage Grid and Utility Computing require data to move freely across the environment without disrupting end-user or application access. Standards-based NFV offers this required non-disruptive data movement across heterogeneous environments, which represents a significant change in the ability to effectively manage NAS environments.

Government and industry regulations have placed new demands on the storage infrastructure right in the middle of flat IT headcount budgets and unprecedented storage growth. Strategic Research Corp. recently published a three-year forecast predicting a seven-times increase in storage capacity but no associated increase in IT personnel to manage the larger pool.

File virtualization technologies like NFV were developed to simplify and automate NAS and unstructured data management while enabling client and application data access.

NFV Benefits

According to IDC, storage administrators must increase their efficiency by 60% just to stay even with the anticipated growth in storage capacity. NFV not only helps administrators meet the storage management challenges of today, NFV drives tremendous benefits.

NFV Components

NFV is based on a number of widely deployed and mature technologies integrated with some newly emerging technologies. Mature technologies include file servers, file systems including recent innovations for clustering, distributing and spanning the wide area networks; along with data protection utilities including snapshot and backup, and global names spaces including DFS and Automount.

However, important functionality has traditionally been missing:

* Active data cannot change physical location due to disruption of user and application access

* Global namespace presentation and management is too complex

* While Automount is prevalent, it has limitations and is not part of the NFS protocol standard

* Identifying and resolving capacity and performance management issues is too manual and labor intensive

* Staging data between online and near line storage is not automated

* Consolidations are continually delayed so the impact on data availability and user disruption are IT labor-intensive and error-prone

The emerging technologies enabling NFV include file management applications, transparent file protocol switching, standards-based global namespaces, and global namespace management.

File Management Applications

NFV enables file management applications that transparently manage active data. Purpose-built applications simplify management tasks and automate file management by identifying capacity and performance issues and then directly resolving those issues. File management applications go well beyond existing tools that provide monitoring capabilities and storage status information. File management applications, with NFV as an underlying foundation, allow administrators to optimize storage instead of simply checking status.

These essential, NFV-enabled network storage applications include:

* Capacity management. Automatically identifies over-allocations at the file server, volume and directory level; and takes corrective action.

* Tiered storage management. Automatically stages data between high-speed and near-line storage; transparently supports service levels without disrupting access.

* Performance management. Automatically identifies performance bottlenecks at the file server, volume, and directory level; and optimizes I/O.

* Consolidation. Pools multiple file servers to appear as one. Can be permanent or temporary as part of consolidations.

* Disaster recovery. Synchronous and asynchronous content distribution across multiple locations.

* Regulatory compliance. Automates regulatory compliance data retention, retrieval and authentication.

Transparent File Protocol Switching

The key to NFV is the ability to manage storage without any user or application service disruption. The batch window continues to shrink while the amount of storage to be managed continues to grow. Management operations must execute without impacting data availability.

Users and applications cannot cope with a file's physical location changing while actively reading and writing data. Transparent File Protocol Switching on the network is therefore required to manage active data.

The key to Transparent File Protocol Switching is the ability to provide location transparency for data actively being accessed without introducing data integrity, data access or performance risks. True switching technology removes the data integrity and access risk by routing traffic, rather than storing persistent data--even file system or global namespace related data.