Hybrid and all-flash memory arrays are arguably the two hottest technologies in storage systems right now. However determining which of these two types of storage arrays is the right one for an organization’s environment is influenced by both cost and production application requirements. In this second installment of my interview series with Tegile System’s VP of Marketing, Rob Commins, we discuss what the tipping point is in going from hybrid to an all-flash memory storage array.
Jerome: A tough decision that organizations face is when to choose which type of storage array should they now buy: a hybrid array or an all-flash memory array. Is there a tipping point that should lead them to choose hybrid over flash?
Rob: The all-flash memory configuration is by far and away faster than hybrid arrays. That is only because there is more flash in the array. However the response times are consistent regardless of configuration. If you are looking at above 125,000 IOPS that is when we recommend organizations jump up to the highest end Tegile system – the Zebi HA2800 – whose configuration has the capability to deliver 200,000 IOPS.
Tegile is very focused in the midrange of the market as that is our bread and butter. This is why it offers both hybrid and all-flash storage arrays. Currently we see the volume of our business going to our hybrid arrays – the Zebi HA2100, HA2100EP and HA2400 – as they deliver IOPS in in the 50,000 to 125,000 range.
So the short answer is, if your applications can drive no more than 200,000 IOPS, a hybrid array will suffice. If your applications can drive more than 200,000 IOPS, an all-flash array is probably the way to go.
Jerome: Flash memory is so much faster and power efficient than hard disk drives (HDDs), do you see a day when HDDs someday become immaterial? In other words, is disk dead?
Rob: There are people who have been saying tape is dead for 30 years. If you just look at the cost per gigabyte curve, a lot of the all flash guys like to say, “Hey, we meet the dollars per gigabyte of spinning disk with flash!”
There is a corner case where they are correct. They will run their data reduction technologies on flash to get that, let’s say a 5x reduction, in their dollars per gigabyte. But they neglect to run those same reduction technologies on the 15K RPM spinning disk they are comparing their solution to. Their caching and deduplication algorithms are actually not that good as they run really, really slow on spinning disk.
So they say, “Hey you cannot do that on spinning disk!“ But Tegile can. Tegile takes that same 5x to 7x data reduction ratio, applies that to SSD and the spinning disk, and that is how Tegile is able to deliver 200,000 IOPS at less than a buck a gigabyte on its all-flash Zebi HA2800.
If you look at a traditional all-flash array and you give them the benefit of the doubt of their marketing claims, they’re running between $5 and $12 per gigabyte. Tegile can deliver high performance flash performance and resolve the cost to a dollar per GB. It is for reasons like this that we think disk has a lot of life left in it.
Jerome: What’s magical about the one dollar per gigabyte price point?
Rob: Really it is an emotional thing. If you look at most home electronics, if you can get a device down below $200, people start buying it. Tegile found that if it told people that they are going to get flash-like performance at less than a dollar a gigabyte, an emotional light bulb goes off.
They know that all-flash arrays are much more expensive. But if you get the price down to a dollar a gigabyte, they do not even want to run a total cost of ownership (TCO) analysis comparison between the products. If a hybrid system is 5x to 12x less expensive than another all flash system, the discussion’s over.
Back to the claims that some of the all-flash guys are making. There is a segment of the market where some all-flash providers are even claiming a million IOPS. So if you are a credit card processing house, and you are trying to transact credit card transactions at Christmas time, an all flash array delivering gobs and gobs of IOPS makes sense. But if you look at the core of the midmarket where most businesses actually operate and where majority of the storage business is, they do not need that kind of performance.
It is kind a bit like the overused automobile metaphor. Everyone loves to look at Ferraris because they are really fast and cool looking. But there are very, very few people that have one. Even fewer people have the Bugatti Phaeton. They are both badass cars but who really “needs” one.
In Part I of this interview series, we talked about how sub-millisecond response times are the new gold standards in storage system performance.
In Part III of this interview series, we will be examining the key technologies that differentiate Tegile from its competitors.
In part IV we discuss the benefits that ZFS brings to a relatively new storage player like Tegile.