Hybrid storage arrays use flash memory in combination with hard disk drives to create storage that balances performance, capacity and cost. Because the majority of the data will ultimately be stored on slower HDD instead of flash memory, the trick is to achieve consistently high performance without 100% flash. The secret sauce the hybrid storage array providers bring to the table is a combination of storage architecture, hardware, and software features.
The Business Value of a Hybrid Storage Array
Time is money, and old storage architectures take too much time. They are too hard to manage and cannot keep up with organizational needs or the random I/O demands of the virtualized data center. Desired business results are often hampered by inadequate storage system performance.
Hybrid storage arrays promise to deliver the dramatic performance benefits of an all flash array at a lower cost than an all flash array. In addition, by combining flash memory and high-capacity HDD in a single system, hybrid storage arrays accelerate access for a broader set of applications than can be housed on a smaller capacity all flash array. Unifying more storage under one modern management umbrella adds to the benefits a business realizes from the storage investment, while subtracting from the overall storage management cost.
Now is the Time
Storage industry veterans from a number of companies recognized the opportunity to combine a new generation of server hardware, flash memory and HDD into a system that could enable IT to deliver the performance businesses seek at a lower cost than either all flash or traditional arrays.
How a Hybrid Storage Array Differs From an All-Flash Memory Storage Array
A hybrid storage array uses flash memory–generally in the form of either PCIe cards or Solid State Disks (SSDs)– in combination with hard disk drives to create server-addressable storage pools. Because not all storage in the hybrid storage array is flash, it is necessary to implement intelligent caching/tiering algorithms to place “hot” data in flash memory and warm/cold data on hard disk drives. The key concept is dynamic data placement in a hybrid storage pool that combines flash memory and traditional hard disk drives.
How a Hybrid Storage Array Differs From a Traditional Array
Many traditional arrays can incorporate flash memory as a cache or as a high performance storage tier. A hybrid storage array is architected for flash memory, and generally adopts a “flash first” approach to storage. In a hybrid storage array, caching/tiering algorithms are often combined with in-line deduplication and data compression–along with cache hardware and specialized software algorithms–to maximize the amount of storage I/O that is satisfied from high speed cache and flash memory.
Because of the “flash first” design, many of the hybrid storage arrays contain only flash memory and high capacity multi-terabyte 7.2K RPM SAS or SATA hard disk drives. In that regard, hybrid storage array providers are bypassing expensive and lower capacity Tier 1 15K SAS/FC and Tier 2 10K SAS/FC hard disk drives, thus minimizing complexity and capital expenses.
Hybrid storage arrays leverage the latest generation of commodity server hardware with multi-core CPUs and higher RAM capacities. This high-performance hardware makes it possible to implement data optimizations such as in-line deduplication and compression without impeding the flow of data.