Much attention has been given to hybrid arrays that couple solid state drives (SSD) with rotating media. And, many industry experts are declaring the demise of high-cost Fibre Channel drives as low-cost Serial ATA drives (SATA), when coupled with a relatively small amount of SSD storage, can provide an extreme boost in performance at a relatively low cost. High-end storage systems already have established the differential between Fibre Channel and SATA with tiering controls. 3PAR has about five years of experience in the autonomic processes involved in moving data between high cost drives and low cost drives. The newest InServ software option announced this week, coupled with enterprise class SSDs, lets 3PAR customers take advantage of the SSD speed without forklift replacements.
3PAR Adaptive Optimization software is a new product option that requires 3PAR System Reporter software, Version 2.7 or above. The algorithms intelligently monitor sub-volume-level performance in context with configurable policies to distribute storage workload across tiers and adapt to changing application demands.
InServ lets storage administrators define a profile for each volume, and tiers of storage within the volume can be designated, for example, SSD, Fibre Channel hard disk (HDD) and SATA HDD. Within each volume, Adaptive Optimization monitors the activity in regions of 128MB. A region is a virtual RAID construct that is essentially a narrow stripe of capacity across many small virtual disks (called chunklets). This granularity allows the system to make autonomous decisions regarding the placement and movement of data either on a default basis, which places the "hot" data on the fastest media, or by controls set by the administrator within the volume policy. Such controls include limitations on the amount of data moved, setting schedules for movement, setting the analysis period, and so on. This allows the administrator to tweak performance based on application knowledge. Additional controls, called QoS Gradients, allow the volume to be managed for maximum performance, which will bias placement to the fastest media, minimum cost, which will bias placement on the least expensive media, or balanced, which is the default setting and allows adaptive optimization to balance between speed and cost of storage.
Each STEC MACH8 SSD in 50GB increments provides high performance via a SATA interface. While individual drives from STEC can be ordered in higher capacities, InServ takes advantage of the parallelization of multiple drives applied to each volume within the array, and can more easily spread SSD capacity across more ports and CPU resources with the smaller capacity drive. SSDs can be added in eight drive (400GB) increments to any InServ F-Class and T-Class Server Storage Array. A small amount of SSD goes a long way. 3PAR analysis shows that 2% to 5% of total storage in SSD provides an optimal boost in storage performance.
The addition of enterprise SSD support with adaptive optimization is another feature that extends the InServ systems feature set.