Tuesday, February 15, 2011

For organizations looking to move to solid state storage beyond the niche, such as for virtualization, VDI, shared storage and NAS, those organizations should consider sustainable storage systems that provide a robust file system and data services, like snapshot, replication, and more, as full native features of the flash memory array itself. In this three part series Storage Switzerland will explore the important ingredients of a solid state only system with a fully integrated file system and data services.

As mentioned above, the problem with most solid state storage systems is that they provide only the basics: fast capacity. Where performance is the only consideration, this basic feature set may be acceptable, since the cost of the SSD array is offset by the increase in revenue generation that comes from removing storage bottlenecks.

Moving solid state to SAN and NAS systems, though, demands much more than pure capacity. If the SSD array does not provide these data services natively, one idea is to add an intelligent storage gateway or “head unit” that does. Architecturally, however, doing so would entail compromises. The head unit introduces another piece of hardware and associated latency between the applications and the flash storage, reducing performance, when the goal is the exact opposite: to raise application performance by eliminating bottlenecks and latency. Second, a single head unit introduces a single point of failure into the environment, reducing availability. Since most performance-sensitive environments are also mission-critical environments, this may be a non-starter. While this can be overcome by clustering, doing so increases costs. Finally, any new piece of hardware must be managed, complicating administration, increasing rack space, power, and cooling costs, etc. If the goal of flash is to increase performance and reduce storage OpEx, adding gateways/heads may be a challenging way to get there.

A potentially better approach is for intelligent data services to be a feature of the flash memory system itself, implemented natively on the system, without any extra hardware and latency. Less hardware means better performance and fewer points of failure, less points of management, all of which improves quality of service. Furthermore, this value-added software could then be designed specifically for the unique attributes of flash, and that would need a fresh look at the file system and how data services are implemented. Features not achievable before without substantial compromises, like primary storage deduplication, are now possible due to the speed of the underlying storage, enabling flash memory systems to deliver superior efficiency and lower CapEx in addition to better performance.

Sustainable Storage systems, such as those from Nimbus Data Systems, follow this approach of offering native data services directly in the flash storage system itself, and doing so makes them much more attractive for a broad range of enterprise storage requirements. This versatility translates into superior ROI. 

In the next part of our series we will analyze the intelligent software features necessary for an enterprise flash system.

George Crump, Senior Analyst