Disk Subsystem Functionality Roadmap.

Magnetic disk storage represents the primary storage technology for most all of the world's s mission-critical, performance-sensitive, and online data. The disk industry's future roadmap promises even more progress and rich functionality. At some point, areal density and pure feeds and speeds progress will slow. The functionality of the disk subsystem will become the primary differentiating factor.

Widespread use of data compression and compaction will emerge to further improve volumetric efficiencies. More intelligence will likely become part of disk controllers and drives as the path toward SAN pushes knowledge of the data closer to the data itself. Architectural enhancements such as migration of data directly from disk to tape (serverless-backup/recovery) will offload significant I/O traffic from the servers creating an outboard hierarchical storage system.

As various RAM chip technologies fall in price, become non-volatile and increase in capacity, expect to see more RAM storage embedded in conventional drives for indexes, directories, and specific-addressable content that will eliminate mechanical movement. Dual-actuator configuration designs have several options and will likely be examined again (they were too costly before).

Virtual disks offer even more functional promise. They allow an any-to-any topology mapping that will greatly enhance heterogeneous SAN-attached devices.