May 14th, 2012 by Mark Kidd
Flash in Tiered Storage [STA 2012]
Since the previous STA Technology Showcase, solid state disks (SSDs) and flash memory have grown more and more common in enterprise storage. Whether as SAS/SATA drives or PCIe add-in cards, the most common use of flash has become high-performance caching and serving as fast Tier 0 storage to complement slower hard disk drives. At this year’s STA event, next-generation tiered flash solutions that demonstrated the performance benefits of combining SSD storage with HDD arrays was sponsored by PMC, HGST, HP, SanDisk, Seagate, Toshiba and WD.
Tiered storage solutions supplement a pool of hard drive-based storage by adding 10-25% flash storage as Tier 0 to create one consolidated volume with improved performance characteristics for frequently changed or accessed files. Tiering with flash storage can improve performance as much as 25x for some applications, but most enterprise storage scenarios which feature a mix of frequently and less-frequently used data will see noticeable performance gains. Adding flash as Tier 0 storage with a tiering controller or software is a low-risk way to significantly improve performance that works with existing SAS infrastructures.
Compared to just caching data, tiering gives both a boost in overall performance as well as a boost in capacity, since the flash storage is added to the total storage of the array.