There are a number of factors that impact the performance of an All-Flash or Hybrid storage system. These systems are all based on the same basic foundation, flash memory acting as storage. In the hard drive era, inefficient software and underpowered storage processors could hide behind the latency of rotational media. Flash storage eliminates this latency and can now stress the components.
In our webinar, “The Future of Flash in 2015“, we identified the components that can impact overall system performance. These are: the NAND flash and controller technology, the efficiency of the storage system software and the processing power of the storage system CPU, also known as the storage controller.
The flash controller not only impacts flash performance but also reliability. It can be enhanced by increasing the amount of RAM available to queue inbound data so that the storage system doesn’t have to wait for data to be organized and written evenly to flash cells. The controller can also adjust the amount of flash that is over provisioned so that it’s more suitable for more write-intensive environments.
The storage controller is essentially the engine that drives the storage system software. The more powerful this engine is the more functionality the storage system can deliver without impacting storage performance. Because the storage media now responds instantly to an I/O request, a faster storage controller can make a difference in how quickly data is moved into and out of the system.
The storage software’s efficiency and the number of features it supports also factor into overall performance of the system. When flash storage systems first came to market they were really more flash appliances than storage systems. They had no real storage features that data centers have come to expect from the storage system. But they were fast, faster than most data centers would ever need.
As vendors came to market with more feature-rich solutions, or added features to flash appliances, the overall performance of these systems was diminished significantly, by about 50% in most cases. They still provided enough performance to meet the data center’s needs but did so with features that IT managers wanted.
It is essential that storage system software used in flash systems be as efficient as possible and be powered by a storage controller that can execute the features without impacting system performance. This becomes a cost-versus-performance challenge that vendors and IT planners need to wrestle with.
In most data centers the flash system that’s selected will more than meet the performance requirements. But some data centers will need to pay attention to these details to make sure the system still provide the features and functionality they also need. Some vendors are providing the ability to turn off certain features or to upgrade the storage controllers in the system, which should provide much longer future use of these systems.