The Search for Sentient SANs Page 2
Vendors Seek Value-added, Network-based Intelligent Services
The fact that the SAN infrastructure already provides intelligent services to assist storage transactions has encouraged SAN manufacturers to seek additional value-added services and thus command higher margins. A few years ago, for example, the SCSI-3 extended copy (third-party copy) standard defined the capability for an intelligent agent to perform direct disk-to-tape block copy processes. This removed the server from the backup process (i.e. serverless backup), streamlined data movement, and helped accelerate the backup routine.
At the time, the industry debated whether third-party copy should be embedded in the fabric switch, in a SCSI-to-Fibre Channel bridge, or in a tape subsystem. Although a few vendors attempted to market switch-based third-party copy, the technology eventually gravitated to the SAN bridges (aka routers) or as embedded functionality within the tape target.
Why? Partly because customers were already burdened with the relatively high cost of fabric switches and did not want to pay a premium for switch-based extended copy. In the end, the market determined that the extended copy function should reside close to the tape target or within the tape library, not dispersed within the network.
This historical example, however, has not dissuaded SAN vendors from claiming new territory for network-based intelligence. Storage virtualization, for example, masks the complexity of hardware storage assets and presents a simplified and more readily manageable view of disparate storage arrays as a single storage pool.
This both streamlines storage administration and enables more efficient use of storage capacity. Storage pooling, for example, allows dynamic allocation of storage if a particular application is exceeding capacity and tapping into unused storage space to balance allocation among multiple servers. Although storage virtualization is still in its infancy, it represents opportunity for a variety of SAN vendors to enhance their product offerings.