There’s no doubt about it: Flash technology is changing the way that IT thinks about storage efficiency, application performance and, yes, life in general. You may have heard the “Flash changes everything” statement from your storage vendor, your peers and even your tech savvy kids but you may still be wondering how to best implement it for optimal impact to your business. At NetApp, we think that question is best answered through an intelligent approach to adding agility to your IT infrastructure and that’s what we had in mind when we introduced the Virtual Storage Tier(VST). And since we did that, our customers have deployed over 15 petabytes of Flash to accelerate over 1.2 Exabytes of their data. That’s a whole lot of Flash but it’s only a little more than 1% of the total storage so the business impact has been huge based on VST’s ability to combine the inherent performance boost of Flash with the unmatched storage efficiency features which are built into Data ONTAP. And now, with Data ONTAP 8.1.1, the Virtual Storage Tier has a new family member… Flash Pool
Flash Pool, like its Flash Cache sibling, implements VST through intelligent caching of hot data thus delivering real time performance improvement with the right mix of Flash and HDD. Flash Pool, is actually a specific type of Data ONTAP aggregate which is composed of both HDD and SSD devices. While Flash Cache (implemented as a PCI-e attached controller cache) accelerates random read operations for all data on the storage system, Flash Pool is enabled for specific data sets and provides caching of random write operations as well as random reads. And since Flash Pool is physically implemented at the disk shelf level, it provides a cache that follows data persistently, even in the event of HA failover events. You can deploy Flash Cache and Flash Pool independently or combine them on the same storage system giving you the ability to tune VST to the requirements of specific workloads-you can use Flash Pool for workloads with lots of random writes and Flash Cache will cover the rest.
So you may be asking: Is Flash Pool mostly a performance enhancer or a way to save money? Great question and here’s the good news: It’s both. We recently put Flash Pool through its paces on a dual controller FAS6210 system running an OLTP workload. We wanted to find out what would happen if we moved the entire workload from a configuration with performance optimized SAS HDDs to one with capacity optimized SATA HDDs. When we added Flash Pool to the SATA configuration, we saw the following:
· Significantly improved response time
· 50% more storage capacity
· 46.3% lower cost per terabyte
· 18% lower $/IOPS
· 26.5% lower power consumption
So it’s kind of a no brainer. With VST, you can meet the majority of your application requirements by combining Flash technology with capacity optimized disk drives- you get the best value without compromise. The best way to use Flash-no doubt about it.
Oh, and one more thing, Flash Pool isn’t just for you high end guys. You may have noticed that Flash Pool was mentioned in our recent announcement of the FAS2220 making NetApp the only vendor combining Flash with this unique intelligent caching approach in the entry-level storage market.
For more background on the NetApp Virtual Storage Tier, here are a few other posts which will shed more light on the topic: