Flash Storage Arrays and the Need for Speed

One of the latest storage breakthroughs that is just now beginning to be popular is the new all-flash-based storage arrays. Flash storage has some tremendous performance advantages over traditional rotational drives. But until recently its costs and limited capacity restricted their use in enterprise applications. Recent advances in the capacities and corresponding reduction in costs of flash storage, however, have opened up many new enterprise applications.

Perhaps one of the most important of these is the all-flash-based storage array network (SAN). Traditionally, storage arrays are optimized to provide efficient and high-performance storage access. In the past, that storage has been mainly composed of disk drives. Some modern high-end storage arrays have evolved to consist of a mix a high-performance SSD drives and larger capacity rotational disk drives. This allowed storage vendors to create a tiered storage environment where hot workloads were directed to the higher-performance SSD drives and cooler workloads used the slower rotational drives.

The newer all flash-based storage arrays can potentially provide far greater levels of performance than even these hybrid SSD / disk based storage arrays. Flash storage can be accessed in microseconds rather than milliseconds. This potential performance is much greater than traditional disk drives. However, because disk- and flash-based storage work in entirely different ways, the technology used in the storage array needs to be redesigned. The technologies built for higher-latency rotational disks don’t work optimally if you just replace the rotational disks with SSDs. The new all-flash-based arrays require very different mechanisms to efficiently read and write data than older disk based arrays. Flash drives utilize random I/O rather than the sequential I/O used in rotational drives. 

This means the new all-flash arrays must be designed to optimize the random I/O patterns used by flash storage. In addition to simply providing higher performance flash storage arrays also need to support many other enterprise-oriented features that businesses have come to depend on, such as snapshots, de-duplication cloning, thin provisioning, and replication. The underlying technology to support all of these features needs to be redesigned to take advantage of the higher-performance potential offered by flash media.

There are a few of these all flash storage arrays beginning to come into the market. One new example is EMC’s XtremIO solution. EMC’s XtremIO is all flash scale-out storage array that was designed from the ground up to take advantage of flash storage allowing it to provide extremely high-performance and flash-optimized enterprise features. XtremIO provides all of the capabilities like snapshot, deduplication, and thin provisioning that you would expect in an enterprise storage array. It uses a scale-out architecture that is built out of highly available, high-performance SAN appliances called X-Blocks to provide linear scalability.

Flash-based storage arrays are the future of storage, delivering improved business value through higher levels of performance, with all the enterprise functionality of traditional storage arrays. Some of the workloads that can make best use of extreme high-performance storage include database, virtual server, and virtual desktop applications.