There has been lots of discussion since EMC's announcement of VFCache, much of it about the implications of said announcement on the storage industry. I've seen all sorts of assertions made by analysts, competitors, wanna bees and prognosticators from all backgrounds – some thoughtful, some diversionary and some that are just down right silly.
There are those that say EMC's entry into the server-side Flash market validates the market for the early entrants. While that may be true in some regards, I will point out that when considered within the entire scope of the announcement, VFCache actually offers significant differentiation from would-be competitors. It is yet to be seen if or how the "established" players in server-side Flash market will respond to that differentiation. (More on this after the break).
There were some who turned this argument around – because VFCache was implemented as a "cache", it couldn't compete with the "established" players in this space – this even though VFCache offers the traditional "Flash-as-DAS" for those that want it. So then they said VFCache was too small to be competitive, especially since some of the other players were talking about 10TB devices and such. I found all this humorous – not surprising, just funny. I always get a chuckle when the success of something revolutionary is measured using the yardstick of the "old" way. Like when EMC introduced the first Flash drives for an enterprise storage array back in January 2008. There were a lot of people (and even a certain competitor's CTO) who asserted Flash was too expensive to have any real utility, and that "nobody was asking for it." Today, barely 4 years later it is hard to find any commercial mid-range or enterprise arrays that don't offer SSDs in ne capacity or another (pun intended).
Then there are those that assert this movement to server-side (Flash) storage represents a full circle return from the 20+ year external storage "diversion," portending the impending doom of the disk drive and/or the external storage array altogether. I assert that for either of these to be true requires an unforeseen discontinuity of pricing: solid state has to get a LOT cheaper than any reasonable projection, or hard disk drives have to get a LOT more expensive. Short of that, there remains a niche opportunity for flash-only solutions, but the sheer economics of $/GB will ensure that the vast majority of the storage market will be dominated by spinning rust for a VERY long time – though increasingly complimented by solid-state persistent storage to deliver the performance required by the typically small subset of any dataset that is "hot" at any given time.
And finally there are those that have made claims that server-side Flash is the precursor to entirely new ways of developing applications, fueled by the heretofore unattainable I/O performance levels delivered by affordable server-side large-scale solid state storage. Some of these pundits go on to assert that server-side solid state technology will drive such a revolutionary overhaul of application development that external storage itself will cease to exist. I personally believe these are fool's forecasts, proffered by those who ignore the reality of history. In the high-tech industry, new technologies rarely supplant the old – neither overnight, nor even over-decades. The IT landscape is littered with still-functioning dinosaurs that may well never be recoded or replaced: mainframes, tape, COBOL, SCSI, Ethernet, perl, , etc. Switching and conversion costs are formidable barriers to overcome. In a world where more than 2/3 of the average IT budget is spent just keeping things running, and the other 1/3 is being invested in storing the growing flood of new information in perhaps in a token few NEW applications to leverage it all, there is little opportunity to invest in rewriting anything. If it ain't broke, don't fix it. The more probable reality is that server-side Flash (like ever-cheaper DRAM) will lead to new ways of building file systems, databases and applications – BUT these will not represent an overnight revolution. Instead, this new “new” will follow the same evolutionary path as have the new technologies that have come before.
With that expression of my humble opinion, I'll spend the 2nd half of this post exploring how I see VFCache fitting into this information-centric world we live in…