NVMe (Non-Volatile Memory express) is the software interface that replaced the SCSI command set for accessing PCIe SSDs. Greater parallelism and lower command queue overhead make NVMe SSDs significantly faster than their SAS or SATA equivalents.

NVMe over Fabrics (NVMe-oF) extends the NVMe API over commodity Ethernet and Infiniband networks to provide PCI levels of performance for remote storage access at data center scale. VAST’s DASE architecture disaggregates CPUs and connects them to a globally accessible pool of Storage Class Memory and QLC Flash SSDs to enable a system architecture that independently scales controllers from storage and provides the foundation to execute a new class of global storage algorithms with the intent of driving the effective cost of the system below the sum of the cost of goods. With NVMe-oF, VAST Containers enjoy the advantage of statelessness and shared-everything access to a global pool of Storage Class Memory and Flash, with direct-attached levels of storage access performance.

Quad-Level Cell Flash (QLC) is the fourth and latest generation in flash memory density and therefore costs the least to manufacture. QLC stores 33% more data in the same space than Triple-Level Cell (TLC). Each cell in a QLC flash chip stores four bits, requiring 16 different voltage levels.

While QLC brings the cost per GB of flash down to unprecedentedly low levels, squeezing more bits in each cell comes with a cost. As each successive generation of flash chips reduced cost by fitting more bits in a cell, each generation also had lower endurance, wearing out after fewer write/erase cycles. The differences in endurance across flash generations are huge – while the first generation of NAND (SLC) could be overwritten 100,000 times, QLC endurance is 100x lower.

VAST’s Universal Storage systems were designed to minimize flash wear by both using innovative new data structures that align with the internal geometry of low-cost QLC SSDs in ways never before attempted and a large Storage Class Memory write buffer to absorb writes, providing the time, and space, to minimize flash wear. The combination allows VAST Data to warranty QLC or PLC flash systems for 10 years, which has its own impact on system ownership economics.

For the first time in 30 years, a new type of media has been introduced into the classic media hierarchy. Storage Class Memory is a new persistent memory technology that is both lower-latency and more endurant than the NAND flash memory used in SSDs while retaining flash’s ability to retain data without external power persistently.

Universal Storage systems use Storage Class Memory both as a high-performance write buffer to enable the deployment of low-cost QLC flash for the system’s data store, as well as a global metadata store. Storage Class Memory was selected for its low write latency and long endurance. A Universal Storage cluster includes tens to hundreds of terabytes of Storage Class Memory capacity, which provides the VAST DASE architecture with several architectural benefits:

10µs Latency

1/10th the latency of Flash

100% Persistent

No need for volatile caching or power protection

1/10th the Cost of DRAM

Enables new buffering and metadata approaches

VAST Servers are stateless containers that run all of the logic of a VAST Cluster in standard x86 servers. Using NVMe over Fabrics, each server enjoys DAS-like, low-latency access to every NVMe Flash and Storage Class Memory storage device.

Containers make it simple to deploy and scale VAST as a software-defined microservice while also laying the foundation for a much more resilient architecture where container failures are non-disruptive to system operation, forming the world’s first web-scale “disaggregated, shared everything” architecture.

• Scalability is better, as the servers don’t need to talk with each other to build a global namespace
• Operations are easier, because containers can be orchestrated and provisioned on the fly
• Resilience is better, since any server can fail without causing a data reconstruction event
• Efficiency is much better because the VAST cluster can execute global codes that enable unprecedented data protection and data reduction

VAST’s Disaggregated, Shared-Everything (DASE) topology is built on top of commodity high-speed networking – easily deploy a VAST cluster on data center fabric without requiring complex storage switching.

• In cases where customers don’t have 100Gb connectivity to build a VAST NVMe Fabric within a VAST cluster, VAST will provide dedicated storage switching.
• For Ethernet environments, NVMe-over-Fabrics can now be deployed on any datacenter-class Ethernet switch.
• For InfiniBand environments, VAST supports NVMe-over-Fabrics running on Mellanox switches.

VAST NVMe enclosures are highly-available, high-density Flash storage JBOFs. The storage processing responsibility has been decoupled from VAST Enclosures such that the system is disaggregated.

Because there is no logic running in the system, organizations can size storage capacity independently from compute to right-size their environment. Since the system is fully fault-tolerant, clusters can be built from as little as one enclosure and can scale to over 1,000 enclosures.

• Raw Capacity 675TB of QLC NVMe Flash and 18TB of Storage Class Memory
• Effective Capacity 573TB at 1:1 ranging to 11.4PB at 20:1
• Networking 4 x 100Gb Ethernet or 4 x 100Gb InfiniBand