Kaminario playing 3D flash chippery doo-dah with its arrays
Now it's just looking for a little TLC
Interview Twitter can be great. There we were, we storage twits, talking about 3D flash, when Kaminario CTO Shachar Fienblit got in touch to say Kaminario was using 3D flash already.
That makes it the first enterprise storage supplier to go 3D NAND, as far as we know, and has an 800GB 3D NAND SSD in its set of flash media. We got in touch with Shachar to find out more.
El Reg: What is your view of 3D NAND, both the MLC and TLC variants?
Fienblit: We already utilise the MLC 3D NAND in our existing product and we are examining the TLC variant. In general we believe that both these technologies significantly expand the trend of cost reduction of the flash media.
Today vendors are applying these technologies with 3X (39-30nm) geometry and in the next few years we will see how flash vendors will continue to shrink the manufacturing geometry while using these 3D and TLC technologies.
This means good things for the SSD media that will continuously expand capacity and drop cost in a very rapid way, which will enable more and more use cases for flash media. Our architecture is well prepared for these SSDs and we will always be fast in delivering these benefits to our customers.
El Reg: Why did Kaminario elect to go 3D flash for 800GB SSDs rather than planar flash?
Fienblit: We have been using it ... for the past six months. The 3D MLC SSD we use comes with relatively high endurance and performance together with a very attractive cost.
El Reg: How does TLC SSD performance and endurance compare to MLC flash for Kaminario?
Fienblit: We are in the process of testing TLC flash SSDs, but do not yet support them. These SSDs will be fully available by the SSD vendors later this year. I cannot share the exact specification as it is under NDA but I can say that some of the TLC SSDs we are evaluating have similar capabilities to 3D MLC SSDs, while others come with lower endurance. We are also examining TLC with 3D technology of 3X nm geometry that delivers endurance that is similar to some MLC SSDs.
El Reg: Will Kaminario use TLC flash?
Fienblit: Yes, since our product has the right feature set to use it. We built an architecture that fits well to very high capacity and density per node, as well as low write amplification. It is a real differentiation we have that is related to the very efficient MetaData management in our system. Two unique things that we are doing to enable high density per node:
- We implemented an adaptive block size algorithm that consumes much less MetaData pointers for the same data set, compared with content address mapping architecture that consumes a pointer for every 4k or 8k of addressable data. All other scale-out, all-flash arrays use [a] content address mapping algorithm that has 2-4x higher MetaData footprint compared with an adaptive block size algorithm.
- We do not store or pin all MetaData in DRAM, so we can attach and address much more capacity per node without a maximum limit on data reduction that is driven by the amount of DRAM per node.
We also write to the SSD in a very efficient way that is tuned with the SSD so the result is extremely low write amplification. This means that our architecture and product is tuned very well for high density TLC SSDs and lower endurance per SSD. Therefore, we will introduce TLC technology very fast to the market, like we already did with 3D MLC NAND.