Raidtec to develop storage systems with SAN Virtualisation ApplianceAmsterdam 15 September 2001 With the demand for on-line storage capacity showing no signs of slowing, the concept of the storage area network to provide both capacity and high availability is now common in broadcast installations. Raidtec is currently developing the SAN further with what it calls storage virtualisation.
The term means dividing the available storage space into virtual volumes, without regard to the physical layout. The main difference between a virtual volume and what is generally termed a logical unit, a single physical device, is that a virtual volume can be created, expanded, deleted, moved and selectively presented, all independently of the storage sub-systems on which it resides. Indeed, it is possible for it to reside on a number of different sub-systems.
The advantages of storage virtualisation, according to Raidtec, include a single point of management of the SAN, flexible allocation of storage space to servers, and sub-system independence to allow users to choose the hardware that best meets their requirements.
Raidtec supports the construction of large-scale storage systems with its SAN Virtualisation Appliance. This consists of a metadata centre that sees the physical storage and allocates virtual volumes and a volume driver at each of the servers on the SAN.
This works because the volume driver resides very close to the hardware level and can thus manage data allocation and retrieval with very low latency and negligible overhead on the host server. At the heart of the Raidtec SAN is a 2Gb/s fibre channel. Using the four-port FibreRAID-SSC, the SAN supports 200MB/s simultaneously across the four ports, with storage capacity from 300 gigabytes to 40 terabytes per controller.
Ad Emmen |
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