The big storage vendors offer hybrid arrays, which are their HDD arrays with added SSD layers. Nimble’s Adaptive Flash System lets enterprises incrementally add SSDs to Tier 0 processing while the HDDs do the storage heavy lifting. Nimble customers can link up to four of the new CS700s into a single storage pool. Tegile is also a hybrid array vendor but has just added a new all-flash array, the HA2800. This is a common trend with hybrid array makers as adoption rises and prices fall for all-flash systems.
All-Flash Arrays with SSDs
These arrays are SSD-only and in performance sit between HDD arrays/hybrid arrays and extreme performance AFAs. These SSD-based AFAs are not all created equal – some of them are HDD arrays replaced with SSD; they see a performance gain but are not optimized for flash. As flash development continues, more and more SSD arrays are purpose built to take full advantage of flash. Pure Storage is an example. Its AFA includes native dedupe and encryption without the overhead of bolting on extra services.
HP offers both hybrid and all-flash arrays dating from previous acquisitions. Its hybrid line StoreVirtual 4335 is based on the LeftHand OS. HP’s StoreServ 7450 all-flash array is its 3PAR technology line. NetApp also sells a hybrid array and has developed an all-flash array for the enterprise, the EF540. EMC’s all-flash entry comes from its XtremIO acquisition. XtremIO optimizes data placement by metadata and handles random access workloads well.
Flash vendors are developing products at a feverish rate, reflecting the growing adoption of flash. HDDs aren’t going anywhere – they’ll be around for a long, long time for capacity and retention. Meanwhile flash provides the higher processing speeds that HDDs cannot. Administrators do not need to wait for more proof points. Start slowly by adopting hybrid flash from your go-to storage vendor, or take advantage of a technology refresh by going straight to AFAs. Flash has gone mainstream. Take advantage of it.
Let’s define a few common terms around flash storage.
· NAND flash memory: Non-volatile NAND serves as the flash memory in most SSDs.
· DRAM flash memory: Volatile DRAM has significantly higher performance than NAND flash but is more expensive because it is not as dense. More DRAM is required for capacity.
· Solid State Drives (SSDs). SSDs incorporate flash memory (mostly NAND these days) and flash controllers in a storage housing. Many array vendors have retrofitted their standard storage devices with front-end SSDs and back-end HDDs.
· Flash controllers. SSDs house firmware flash controllers in their housing. The controller communicates between the flash memory and the host device, manages the directory, and maintains quality control.
· DRAM modules. SSDs can contain DRAM but because of the density issue more commonly contain NAND. A few high performance flash vendors use DRAM modules for higher processing and array-level management.
Christine Taylor is a well-known industry watcher.
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