As I was writing in June 2016, going against the grain has its merits and can bring the most unexpected seeds to grow and blossom. Pure Storage had surprised us in May 2016 with their All-Flash Array (AFA) for unstructured storage: the FlashBlade and its purpose-built architecture, especially its unique – how to say it differently – Flash Blades. We’re now a year forward, and I’m very pleased to be among the happy few who were briefed about Pure Storage’s most recent innovation – or should I say revolution?
A king is born: welcome FlashArray //X
Pure Storage have been quiet and yet they did not sleep on their laurels, far from it. Today Pure Storage is announcing their latest innovation, the FlashArray //X, which they claim to be the first mainstream 100% NVMe AFA to hit the market.
The FlashArray //X is Pure Storage’s response to ultra-fast throughput and ultra-low latency operation levels required by the most demanding mission-critical workloads such as SAP, SAP HANA, Microsoft SQL Server and SAS to name only a few. It can also be used for top-of-rack DAS replacement cases such as Splunk, Cassandra, MongoDB, PostGresSQL, MySQL, Redis and others.
The storage industry is moving fast towards NVMe adoption as SSD becomes the new normal (or shall we say legacy) and HDDs are further moved out of Tier1 / Tier2 to colder tiers for cheap mass storage use cases. The extreme performance improvements performance brought forth by NVMe (lower latency, higher IOPS and the promise of massive I/O parallelization) challenge vendors to further optimize existing architectures inherited from times when one I/O queue per drive was the standard. Pure Storage have understood well the challenges and have completely re-thought the way Flash memory is addressed and managed in their FlashCard Modules and with their FlashCard Software.
The //X series thus becomes Pure’s high-end AFA for Tier1 workloads and high-performance block storage, adding a performance tier over the //M series, Pure’s general purpose AFA for Tier2 workloads and VM storage.
FlashBlade Experience and Architectural Takeaways
Pure Storage have leveraged their experience with the FlashBlade to design an NVMe AFA that aims to tackle the challenges that arise with larger SSD drives. Some of these challenges were already present among the reasons that drove Pure Storage to take radical design decisions for the FlashBlade. Others inefficiencies to be addressed included the small data pipe between compute and flash (maximum of 1 queue vs theoretical maximum of 65535 queues for NVMe) and the inherent design of current SSD drives where functions such as the Flash Translation Layer (FTL), Garbage Collection and many others exist in each and every single drive.
As with the FlashBlade, the decision was taken to use flash chips raw capacity exclusively for data storage purposes, to eliminate the FTL and to move flash management functions at a higher level, i.e. in software. DirectFlash Software is a new software module within the Purity Operating Environment. Flash management functions that were local to flash drives are now executed globally, across the entire FlashArray domain. These functions, that cover garbage collection, allocation, I/O optimisation and error correction are now much more efficient.
These engineering improvements allow DirectFlash modules to present 100% of the raw flash capacity to the FlashArray instead of reserving part of its capacity for management functions. The DirectFlash modules are connected through NVMe and are managed by the DirectFlash Software. This allows for direct, raw flash access to the software. Three raw capacities will be available: 2.2 TB, 9.1 TB and 18.3 TB.
Nitro for mission-critical workloads
In terms of performance, Pure Storage claims that thanks to DirectFlash Software the FlashArray //X operates in the range of 100’s μs latency times while delivering consistently an average five-fold performance increase compared to SSD drives.
At this speed of operation, the transport layer between the array and the compute nodes becomes the bottleneck. The //X comes equipped with 16 Gb FC ports and 10/40 GbE Ethernet iSCSI ports. We expect to see more news on the connectivity front from Pure Storage as the development goes through, especially NVMe-oF (NVMe over Fabrics). NVMe-oF over RDMA is likely to be expected, though Pure plans to deliver NVMe-oF support in 1H2018. It would be interesting to understand whether 25/50/100 GbE will be supported in the future.
In terms of form factor and expansibility, the FlashArray //X is a 3U enclosure (similar to the //m50 and //m70) with 20 modules slots, each divided into two capacity packs (10 slots each). Expansion shelves are also available, though they can take up to 24 modules (12 per capacity pack). Click below to see a video preview of the //X.
Beyond the technical aspects, the //X benefits from the same data services provided by Purity OS that are already leveraged by the //M series: deduplication & compression, RAID-3D, HA, QoS and encryption. On the side of data protection, snapshots & replication features are provided as well. Looking at extensibility beyond Pure boundaries, it’s worth nothing that Pure Storage & Cohesity have recently announced full end-to-end integration between their solutions. It’s safe to bet that //X will benefit from this as well.
Evergreen all the things!
Pure Storage had pre-wired support for SAS and NVMe in their FlashArray chassis and midplane when it was released in 2015. The new FlashArray //X70 controllers enable NVMe communication on these chassis. As a consequence, customers who have //M50 and //M70 arrays should be able to seamlessly evergreen (upgrade) to the FlashArray //X. We asked Pure Storage about potential downtime during the upgrade process.
Pure informed us that the process would be fully online and seamless to the users. During an upgrade, the older controllers are replaced with new NVMe-capable controllers, SSD modules are replaced with DirectFlash modules and customers also get a their //M bezel replaced with a beautiful, brand new //X bezel. Customers can also decide to mix DirectFlash modules and SSD drives in the same chassis. What a time to be alive!
Per Pure Storage press release, FlashArray//X with both 2.2 and 9.1 TB DirectFlash Modules is available to order today, will be shipped as a Directed Availability release starting in early Q2 FY2018 and is fully supported for production use. General Availability of FlashArray//X, which will support both 18.3TB DirectFlash Modules and upgrades from existing FlashArray//M systems, is expected in early 2H FY2018.
I am genuinely excited by Pure Storage’s audacious entry in the NVMe AFA market. They are not following anyone and instead of walking the well-trodden path of hardware commodity, they are defining a new class of storage devices. The technology is best-in-class and Pure’s engineers seem to have successfully capitalized on the innovations brought forth earlier in 2016 with the radically new FlashBlade platform.
Beyond the technical feats, the extra « cherry on top of the cake » part of the announcement is the upgrade path offered to //M50 and //M70 array owners. Evergreen Storage (one of Pure Storage’s ownership models), which promises no forklift upgrades, is a competitive feature that few if none others have in the industry. The ability of upgrading online and without downtime the FlashArray controllers as well as the DirectFlash Modules is nothing short of a tour de force with flawless execution.
Customers who invested in Pure Storage hardware and subscribe to Evergreen Storage will appreciate the commitment. As a final word, I believe and hope that from this bold announcement they will gain not only momentum, but also the appropriate level of recognition in financial markets. I’ll be particularly looking at how the industry receives this announcement, as well as how markets react (follow PSTG.K stock ticker here).