Flash and SDS: Destined to be together?
In our previous two articles, we explained how software is becoming the fundamental core of storage systems. An open software centric approach as opposed to a special proprietary hardware system is the fundamental reason for the decline of traditional storage systems. Software Defined Storage (SDS) breaks the hardware vendor lock in and in doing so returns value and savings back to the user. In recent years we the ubiquity of Flash based storage has become yet another nail in the coffin of traditional storage. In this article we expand on why flash storage combined with SDS has made traditional high end storage irrelevant.
RIP Traditional High Performance Storage.
It is all about IOPS. Traditional Storage can only achieve high IOPs by adding large amounts of disk drives within a single system. To achieve the performance a legacy high-end disk array may have to contain hundreds or even thousands of disk drives. Hand in hand with that comes increased data centre space, power and cooling which all adds up to extra cost. Flash based storage delivers IOPS up to 100 x that of a standard HDD. The spin-off is a flash array requires far less datacentre space. Also because flash has no moving parts it also saves on power and cooling. When you compare cost per IOP Flash storage will deliver savings of over 10x compared a traditional high end array. Quite simply legacy high performance storage has reached the end of its useful and usable life.
The Table below demonstrates just how flash has reduced cost per IOP in the datacentre.
|Storage systems||Storage Medium||System Selling Prices||IOPS||Performance cost (USD/IOPS)|
|High-end disk array||Hard drives||150k – 1.5m USD||30-200K||> 30 USD|
|High-end array configured with pure flash||SSD||1m - 40m USD||1-3M||0.8-3 USD|
|Hybrid arrays||SSD and Hard drive||15k – 310k USD||100K-150M||0.08 – 0.8 USD|
|All Flash Array||SSD||62k- 310k USD||200K-2M||0.08 – 0.3 USD|
Note: There is a huge variety of products on the market. The table above only provides a rough comparison of costs and performance of several kinds of equipment; specific products might show some variation, but the magnitude should be accurate.
Note 2: All values were converted and estimated from China Ren Min Bi and is not a reflection of actual values. Conversion rates and estimates may vary depending on market changes
Flash means Savings
When calculating cost v performance, it’s clear that Flash is not the “luxury” technology that some people believe it to be. Rather it is actually the most cost effective option for performance-critical applications. Quite simply Flash will save you money.
Hybrid isn’t the answer
In order to stay relevant, we have seen numerous developments from the traditional disk vendors. Most traditional disk vendors have launched all flash arrays and hybrid arrays. But in many cases they have been built using a legacy architecture that does not support flash array level latency. Effectively this means that old architecture is housing flash disk but not able to drive data to that flash at fast enough speeds. Simply placing a flash disk in a traditional array enclosure will not deliver the performance that flash promises. In addition, these Hybrid arrays cannot be easily shared across multiple systems. Having to isolate each flash array to serve a single system leads to unacceptable inefficiency.
SDS puts the right data to the right place
SDS combined with Flash cache is the only way to get optimum IOPS per dollar. Adding a flash array into an environment built on legacy storage, using SDS to flexibly allocate the storage across multiple systems and using flash cache to derive benefit from flash where and when it is needed can and does produce surprising and spectacular results. It’s the most cost effective way to drive performance. Freestor recently applied this solution in a large bank in China. The results surpassed the end users’ expectation. The Freestor solution delivered an 8-fold increase in business application performance, yet delivered huge cost savings over the banks alternative expansion proposal from their traditional existing storage vendor.
So where is the Freestor magic?
In addition to the Falconstor ‘s Freestor cross-platform unified management and automated allocation mentioned above, there are two specific technologies that enhance the Freestor proposition.
FalconStor’s SafeCache technology utilises high performance flash disk set up as a cache pool to serve the entire data centre. Data sent by host servers is continuously written on flash media at true flash speed, it is then copied to traditional primary storage media asynchronously. SafeCache is policy based enabling automation based on pre-set policies and as the name suggests it also provides safety against data loss or corruption.
2. Write acceleration HotZone
HotZone is another function for speeding up data access of the storage under FreeStor management. It has been developed for Random Access applications, analysing the most frequently accessed data and placing it in a “hotzone” on flash storage for much faster access and read times. The hotzone technology is intelligent and analyses the data profile in real time. If the more frequently accessed data changes, less frequently accessed data will be moved from the HotZone back onto traditional primary storage.
Out With The Old and In With The New.
All flash arrays are in their own right a technology which was putting pressure on traditional approaches to high performance storage. When combined with FreeStor, not only is the full promise of Flash realised, with unbeatable price performance. With Freestor, Flash Storage can sit on top of cheap commodity traditional storage to deliver blistering performance when and where it’s needed with a cost effective resting place for data that does not need to be processed at speed. It seems hard to believe, but the net result of combining moderate amounts of Flash Storage with Freestor SDS is to achieve the best possible performance whilst materialising genuine cost savings.
When users put this to the test, they also reach the same conclusion, the days of the legacy high-end storage arrays are over.