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.<ref name="MicheloniMarelli2012">{{cite book|author1=Rino Micheloni|author2=Alessia Marelli|author3=Kam Eshghi|title=Inside Solid State Drives (SSDs)|url=https://books.google.com/books?id=S8xRtkF7hUkC&pg=PA62|year=2012|publisher=Springer|isbn=978-94-007-5145-3|page=62}}</ref> 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.
== Implementations == <!-- please only add products covered in WP:SECONDARY sources at adequate depth --> Some commercial products for building hybrid arrays include: * Adaptec demonstrated the MaxIQ series in 2009.<ref>{{cite web |author=Charlie Demerjian |url= http://www.semiaccurate.com/2009/09/09/adaptecs-maxiq-caches-raids-ssds/ |title= Adaptec's MaxIQ caches RAIDs with SSDs |publisher= SemiAccurate |date= September 9, 2009 |access-date= September 6, 2024 }}</ref> * 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.<ref>{{cite web |last= Larry Dignan |url= http://www.zdnet.com/blog/btl/emc-unveils-vfcache-targets-fusion-io/68657 |archive-url= https://web.archive.org/web/20120206220809/http://www.zdnet.com/blog/btl/emc-unveils-vfcache-targets-fusion-io/68657 |url-status= dead |archive-date= February 6, 2012 |title=EMC unveils VFCache, targets Fusion-io |publisher= ZDNet |work= Between the Lines |date= February 5, 2012 |accessdate= October 10, 2016 }}</ref><ref>{{Cite news |title= One day later: EMC declares war on all-flash array, server flash card rivals: Rolls out XtremIO array, renamed VFCache |date= March 5, 2013 |work= The Register |author= Chris Mellor |url= https://www.theregister.co.uk/2013/03/05/emc_xtremsf/ |accessdate= October 10, 2016 }}</ref> * Fusion-io acquired ioTurbine in 2011,<ref name="io">{{cite web |url= https://www.theregister.co.uk/2013/06/25/fusionio_spins_ioturbine_faster/ |title=Fusion-io spins up ioTurbine, enhances server flash caching |work= The Register |accessdate= October 10, 2016 }}</ref> and the product line it acquired by buying NexGen in 2013.<ref>{{cite web|url=https://www.theregister.co.uk/2013/04/24/fusion_io_nexgen/|title=Fusion-io buys NexGen|work=theregister.co.uk |accessdate=2015-03-26}}</ref> * Hitachi Accelerated Flash Storage (HAFS) used together with the Hitachi Dynamic Tiering software<ref>{{citation |url=http://www.computerweekly.com/feature/Big-storage-turns-the-tide-in-the-hybrid-flash-array-market |title=Big storage turns the tide in the hybrid flash array market |work=Computer Weekly |date=September 2013 |accessdate=2015-03-26}}</ref> * IBM Flash Cache Storage Accelerator (FCSA) server software<ref>{{cite web|author=The SSD Guy |url=http://thessdguy.com/ibm-adds-server-side-caching/ |title=IBM Adds Server-Side Caching |publisher=The SSD Guy |date=2013-08-20 |accessdate=2013-12-23}}</ref> * Intel's Smart Response Technology for desktop * Intel's Cache Acceleration Software for servers and workstations * LSI CacheCade software for their controllers<ref>{{cite web|url=http://www.storagereview.com/lsi_megaraid_cachecade_pro_20_review|title=LSI MegaRAID CacheCade Pro 2.0 Review|accessdate=2015-03-26|work=storagereview.com|archive-date=2015-04-02|archive-url=https://web.archive.org/web/20150402105452/http://www.storagereview.com/lsi_megaraid_cachecade_pro_20_review|url-status=dead}}</ref> * Marvell's HyperDuo controllers<ref>{{cite web|url=http://www.cnet.com/8301-32254_1-20027657-283.html|title=Hands-on with the Marvell HyperDuo hybrid storage controller |accessdate=2015-03-26 |publisher=CBS Interactive|work=CNET}}</ref> * Microsoft's Automated Tiering (since Windows 2012 R2) * NetApp's Flash Cache, Flash Pool, Flash Accel<ref>{{cite web|url=https://www.theregister.co.uk/2012/08/21/netapp_server_flash/|title=NetApp: Flash as a STORAGE tier? You must be joking |accessdate=2015-03-26 |work=theregister.co.uk}}</ref> * Oracle Corporation markets products such as Exadata Smart Cache Flash, and the FS1 flash storage system.<ref>{{Cite news |title= Oracle crashes all-flash bash: Behold, our hybrid FS1 arrays: Mutant flash/disk box a pillar of storage: It's axiomatic |date= September 30, 2014 |work= The Register |author= Chris Mellor |url= https://www.theregister.co.uk/2014/09/30/the_fs1_pillar_of_oracle_arrays_storage/ |accessdate= October 10, 2016 }}</ref> * Microsoft ReadyBoost allows personal computers to use USB flash drives (or any solid-state media) as cache. * Nvelo DataPlex SSD caching software was announced in 2011,<ref>{{cite web |url= http://www.thessdreview.com/our-reviews/nvelo-dataplex-ssd-caching-software-review-seven-msata-ssds-prove-an-amazing-concept/ |title= NVELO Dataplex SSD Caching Software Review - Seven mSATA SSDs Prove An Amazing Concept |work= The SSD Review |date= December 4, 2011 |author= Les Tokar |accessdate= October 10, 2016 }}</ref> and was acquired by Samsung in 2012.<ref>{{cite web |url= http://www.anandtech.com/show/6518/samsung-acquires-ssd-caching-company-nvelo |archive-url= https://archive.today/20131223163536/http://www.anandtech.com/show/6518/samsung-acquires-ssd-caching-company-nvelo |url-status= dead |archive-date= December 23, 2013 |title=Samsung Acquires SSD Caching Company NVELO |publisher=AnandTech |author= Kristian Vättö |date= December 16, 2012 |accessdate= October 10, 2016 }}</ref> * SanDisk FlashSoft for Windows, Linux, and vSphere<ref name="io"/> * Products are offered by vendors like AMI StorTrends,<ref>{{cite web|author=Ian Barker |url=http://betanews.com/2014/01/27/ami-stortrends-3500i-offers-high-performance-storage-for-smaller-enterprises/ |title=AMI StorTrends 3500i offers high performance storage for smaller enterprises |publisher=BetaNews |date=2014-01-27 |accessdate=2014-10-17}}</ref> Tegile Systems, Reduxio, and Tintri.<ref>{{cite web|url=https://www.theregister.co.uk/2013/04/09/blind_spot/ |accessdate=2015-03-26 |title=Mutant array upstarts feast on EMC, NetApp's leavings|work= The Register }}</ref> * ZFS using hybrid storage pools, are used for example in some Oracle Corporation products.<ref>{{cite web|url=http://www.enterprisestorageforum.com/san-nas-storage/oracles-flash-friendly-sun-zfs-storage-is-ready-for-new-sparcs.html|title=Oracle's Flash-Friendly Sun ZFS Storage Is Ready for New SPARCs|date=3 April 2013 |accessdate=2015-03-26 |work=enterprisestorageforum.com}}</ref>
== See also == * Hybrid drive{{spaced ndash}} built-in flash cache, handled by firmware * Automated tiered storage{{spaced ndash}} another name for hierarchical storage management * The "five-minute rule" for caching
== References == {{Reflist|30em}}
Category:Data management Category:Solid-state caching Category:Memory management software