Speeding Up Flash Storage Via Software

How to get the most out of flash storage is a subject of much research and innovation in the storage industry. One choice is to use software, an approach IBM has chosen with its new FlashCache Storage Accelerator (FCSA).

FCSA is server-hosted caching software for IBM’s System x servers, BladeCenter and Flex System products. FCSA captures all disk read I/Os and copies the requested data to server-side flash drives. Additional access to this data then comes from server-side flash. Note that FCSA supports read-only cache. IBM uses a write-through cache approach where all write I/O passes directly through to primary storage.

FSCA integrates with IBM's other flash products and can work with a mix of flash and HDDs. Although FCSA interacts directly with other IBM flash products, the back-end disk arrays do not have to be IBM’s.

As the name implies, FCSA’s purpose is to accelerate the performance of flash (IBM claims up to 2.5 times improvement). This is achieved through software algorithms that maximize flash as cache working in conjunction with hard disk drives. According to IBM, no turning of data placement of hot data is needed as the software adapts to changing workloads.

[Check out some innovative storage technologies that were showcased at VMworld in "Finding New Ways To Boost Storage Performance."]

Of course, IBM’s FCSA is a proprietary system, but the technology provides some insight into the broader market and where it might be headed. Here are three key takeaways.

•The flash market is real: FCSA is part of the IBM Flash Ahead initiative, but other major vendors also are emphasizing the importance of flash. In addition, there are numerous very good flash storage architecture options available from smaller companies, and a number of them are doing quite well commercially. However, at some point, a market consolidation is likely to take place, and the major vendors are positioning themselves to benefit from this.

•Newer applications need flash-based performance: How much flash is enough? For overall storage portfolios where the majority of accumulated data is fixed content (very little can be described as “hot”), a relatively small amount of storage needs to be flash. That is not always the case. For example, although traditional applications (such as OLTP) may very well benefit from higher speed to perform more transactions in the same period of time, newer applications and processes can also be drivers for flash-based performance. These include big data, VDI, taking advantage of even denser virtual server consolidation and on-demand computing in cloud scale infrastructures. Thus, a software-based flash product, such as FCSA could prove beneficial.

•Software can help take more advantage of flash: Software has long been the not-so-secret ingredient in conjunction with cache technologies that improve storage performance. Traditional, controller-based storage array systems have also long taken advantage of software, especially caching algorithms, to get more out of the storage that the controller manages. Flash caching management software such as FCSA simply extends that concept, although in this case, the software is server-based rather than controller-based.

Mesabi Musings

Even if you are not a customer of a particular major IT vendor, you should pay attention when those vendors announce major products and initiatives because they may eventually impact the broader market. Such a case is true with IBM’s FlashCache Storage Accelerator. The use of software, such as FCSA, can significantly accelerate and boost the performance of flash. FCSA isn'tlikely to be the only shoe to drop to illustrate this point, but IBM’s size and market position makes this announcement one that will impact both customers and competitors.

IBM is a client of David Hill and the Mesabi Group.

Find out about the impact of VDI on storage infrastructures and innovative technologies that use RAM, flash and clever software to tame the VDI storage beast in Howard Marks' session, Storage Solutions for VDI at Interop New York this October.