There are many types of implementations of solid state or flash storage systems. At Evaluator Group, we regularly field questions and work on projects regarding solid state storage with our IT clients. In addition to the performance explanations and evaluation guide for solid state, we find it necessary to categorize the different implementations to aid their understanding.
The categorizations do not necessarily match what vendors would say in positioning their products. The important point is categorization has served us well in communicating to our IT clients. However, we understand that nothing is static in the area of storage. Like the technology, these explanations will evolve with new developments.
Here are the categories and explanations that have worked well so far:
- All-solid state (flash) storage systems – These are new systems designs for solid state from the start. These designs optimize performance for the given amount of system hardware.
- Hybrid arrays in a new design system – Hybrid arrays use both solid state (usually in the form of Flash SSDs) and hard disk drives (HDDs) with the idea that large capacity HDDs will decrease the overall price of the system. As a new design, all I/O goes through the SSDs and the HDDs serve as backing storage.
- All-solid state (flash) storage systems based on traditional storage systems with major modifications – These are traditional storage systems designed for spinning disks but modified to take advantage of solid state with the addition of embedded software. The Evaluator Groups looks at the design changes made to determine the significance.
- Hybrid arrays based on traditional storage systems – This large segment includes the traditional storage systems designed for spinning disks where solid state drives (SSDs) are added for cache and/or tiered storage. In these systems, small percentages of SSDs will max out the performance of the system quickly, increasing the aggregate system performance by 2x to 4x.
- As technology evolves, there will be changes to these categories. Certainly, acquisitions will occur – changing what vendors offer and product positioning. Over time, more extensive changes will be made to traditional systems that are limited by their spinning disk designs.
The biggest evolution of all will be the introduction of new solid state technology. Forward-thinking system designers have anticipated this and will seamlessly (and optimally) advance to the new technology when the economics are favorable. This is one of the reasons we use the solid state storage terminology rather than wholly referring to only the current implementation of NAND flash. We will adapt out categorization used with our IT clients to fit the current implementation. Meanwhile, it is great to see the continued advances in technology and implementations for storage systems.
(Randy Kerns is Senior Strategist at Evaluator Group, an IT analyst firm).