Beyond SSD: Flash is More than Faster Disk

Edward Lee / Mar 15, 2012

Ed is an architect at Tintri. Prior to Tintri, Ed was the Principal Systems Architect at Data Domain, and a key contributor to the first and subsequent releases of Data Domain’s file system. He w...more

Robin Harris of Storage Mojo in his recent article, "Are SSD-based arrays a bad idea?" and Matt Kixmoeller of Pure in his response, "The SSD is Key to Economic Flash Arrays,” presents interesting perspectives on whether or not SSDs are the best technology for building flash-based arrays.  Robin argues that by rethinking how flash can be packaged outside the SSD box, you can achieve better performance, reliability, cost and flexibility.  And these observations are supported by the experience of existing flash-based storage vendors who have developed their own custom flash modules and packaging.  Matt argues that SSDs provide an industry-standard product that requires less investment to leverage, better economies of scale, and rapid improvement in technology.  These are also very valid points.

What is missing in this discussion, however, are the broader ramifications of flash technology on the evolution of storage products.  Is flash just a better performance, higher density replacement for disk or is there more?  What will happen when everyone has more IOPS than they need?

With flash, we can finally remove a key mechanical barrier to scaling the performance of not only storage systems, but computing systems in general.  Going forward, CPU, network and storage can now all scale with improvements in semiconductor technology.  When transistors replaced vacuum tubes, we got more than just compact radios; we got simpler, more powerful systems.  Similarly, flash is a catalyst that will enable far greater levels of automation and functionality from storage and computing systems than is possible today.

I tend to think of the value of a new technology as the product of its simplicity times its functionality:

value = simplicity * functionality

We’ve been thinking about the same questions here at Tintri as we continue to build out our VM-aware storage appliance. In fact, we recently wrote about different approaches to using flash storage in a 3 part blog series.

An obvious way flash promotes simplicity is by eliminating performance bottlenecks, but as flash enables more dense storage systems many of those gains will be converted to problems in quality-of-service.  A more significant way flash promotes value is by providing a better building block for constructing storage systems: flash promotes simplicity by enabling higher levels of automation and allows the implementation of more powerful functionality.  That leads to much higher value, but only if we think outside the storage box and treat flash as more than just a faster, denser disk.