Hybrid array

A hybrid array is a form of hierarchical storage management that combines hard disk drives (HDDs) with solid-state drives (SSDs) for I/O speed improvements. Hybrid storage arrays aim to mitigate the ever increasing price-performance gap between HDDs and DRAM by adding a non-volatile flash level to the memory hierarchy. Hybrid arrays thus aim to lower the cost per I/O, compared to using only SSDs for storage. Hybrid architectures can be as simple as involving a single SSD cache for desktop or laptop computers, or can be more complex as configurations for data centers and cloud computing. Some commercial products for building hybrid arrays include: Adaptec demonstrated the MaxIQ series in 2009. Apple's Fusion Drive Linux software includes bcache, dm-cache, and Flashcache (and its fork EnhanceIO). Condusive's ExpressCache is marketed for laptops. EMC Corporation VFcache was announced in 2012. Fusion-io acquired ioTurbine in 2011, and the product line it acquired by buying NexGen in 2013. Hitachi Accelerated Flash Storage (HAFS) used together with the Hitachi Dynamic Tiering software IBM Flash Cache Storage Accelerator (FCSA) server software Intel's Smart Response Technology for desktop Intel's Cache Acceleration Software for servers and workstations LSI CacheCade software for their controllers Marvell's HyperDuo controllers Microsoft's Automated Tiering (since Windows 2012 R2) NetApp's Flash Cache, Flash Pool, Flash Accel Oracle Corporation markets products such as Exadata Smart Cache Flash, and the FS1 flash storage system. Microsoft ReadyBoost allows personal computers to USB flash drives as cache. Nvelo DataPlex SSD caching software was announced in 2011, and was acquired by Samsung in 2012. SanDisk FlashSoft for Windows, Linux, and vSphere Products are offered by vendors like AMI StorTrends, Tegile Systems, Reduxio, and Tintri. ZFS using hybrid storage pools, are used for example in some Oracle Corporation products.