February 1, 2013 — Ken Clipperton
2012 saw a lot of discussion–some would say hype–over flash memory-based storage for the enterprise. Vendors are promoting various approaches to bringing flash memory storage to the data center. DCIG believes that Flash Memory Storage Arrays are poised to address not only special I/O-intensive use cases, but to begin displacing traditional storage arrays in many data centers.
In order to help organizations make faster and better informed purchasing decisions regarding flash memory storage arrays, DCIG is in the final stages of preparing the DCIG 2013 Flash Memory Storage Array Buyer’s Guide. Scoring and ranking tables will enable end users to do “at-a-glance” comparisons between many different flash memory storage array models, and our standardized data sheets will facilitate side-by-side comparisons.
Flash Memory Storage Arrays Poised for Ascendancy in the Data Center
Flash memory storage arrays are getting attention because they are helping organizations achieve results that matter to them. These include the successful deployment of thousands of virtual desktops and resolving application performance issues that could not be cost-effectively addressed by traditional disk-based storage systems. Savvy businesses are discovering that they can get an acceptable ROI and substantially improve their overall return on data center assets by adding flash to their storage environments.
Companies in any of the following three situations in 2013 especially ought to give Flash Memory Storage Arrays serious consideration as an alternative to traditional arrays:
- Virtualizing data centers for the first time. These companies can simply skip the traditional large array, leap-frog the competition, and achieve a better return on their virtualization investments.
- Nearing a virtual infrastructure refresh with storage arrays that are 3+ years old and where performance, reliability, or maintenance costs are a concern.
- Considering building another data center because they are approaching space, power, and/or cooling capacity in current facilities.
Because we believe Flash Memory Storage Arrays will increasingly be evaluated as replacements for traditional arrays, the DCIG 2013 Flash Memory Storage Array Buyer’s Guide will include arrays that meet the following minimum criteria:
- Available as appliance. Incorporated into rack-based data centers in a quick and familiar way. Fitting into data center design as a replacement for another storage array.
- Support one or more SAN protocols (iSCSI, Fibre Channel, FCoE, Infiniband).
- Support an all-flash configuration of the array.
- Support flash as the permanent home for data, not merely as cache.
We are also incorporating most of the criteria used in evaluating traditional arrays into the DCIG 2013 Flash Memory Storage Array Buyer’s Guide. In addition, this Buyer’s Guide will include a new scoring area called “SSD Management” that reveals how much attention a vendor has given to addressing the weaknesses of flash memory in an enterprise storage environment.
Flash Memory Optimization is Important
Like every other type of storage media, flash memory has strengths and weaknesses. In the case of flash memory, these weaknesses were well publicized as reasons why flash was not appropriate for enterprise storage. However, storage vendors have successfully addressed flash memory’s weaknesses through a variety of techniques, including:
- Write Coalescing
- Variable RAID Stripe Sizing
- Data Aging Timer Tuning
- Inline Deduplication
- Block Level Compression
- Hardware Accelerated Compression.
One weakness of flash memory is that an entire block of flash memory must be erased and then re-written whenever data is written to a non-empty block. Another weakness of flash memory is that it supports a limited number of write cycles. Write Coalescing addresses both of these weaknesses, and has been implemented in more of the flash memory storage arrays we evaluated than any other flash management technique.
Write Coalescing involves the buffering and/or coalescing of writes to match erasure block size (EBS) of the underlying flash media. This technique reduces the number of write-to-flash operations and program-erase cycles that are incurred in order to store a given amount of data. As a result, write coalescing enhances both the long term performance and the life expectancy of flash memory.
Write coalescing, and the other techniques listed above, have enabled storage vendors to create storage systems that are not only high-performing, but that are also highly reliable and that possess a useful life that easily equals or exceeds traditional storage systems.
DCIG believes that Flash Memory Storage Arrays are ready for the enterprise data center, and that the enterprise data center is ready for Flash Memory Storage Arrays. We are pleased that beginning in February 2013, the DCIG 2013 Flash Memory Storage Array Buyer’s Guide will become a resource that helps decision-makers make faster and better storage purchasing decisions.
Update: The DCIG 2013 Flash Memory Storage Array Buyer’s Guide is now available. It may be downloaded for no charge with registration.