Storage Developer Conference

RDMA-enabled storage protocols (including SMB3, NFSv4, NVMe over Fabrics, etc), and RDMA protocols (RoCE, iWARP, Infiniband, etc) are being extended to enable remote access to Persistent Memory. Data access at ultra-low remote latency, with high fidelity to local semantics, are goals which are well within reach. Beyond the data itself, can other aspects of storage, such as security and data integrity, be addressed with similar network-based solutions, without upper-layer or CPU interaction? What additional types of protocol extensions might be envisioned to provide similar latency and offload benefits from storage and network adapters, for these other important storage attributes?

This talk will explore the landscape of existing protocol-based access to Persistent Memory, and prioritize additional requirements which merit consideration. It will present a set of architectural tools, with practical protocol implementation approaches, to extend the benefits of RDMA to a broader range of storage solutions based on emerging memory storage technologies.

In this presentation, we introduce accelerated NVMe over fabrics (NVMe-oF) target and host solutions with SPDK (storage performance development kit) library. SPDK vhost is a userspace target designed to extend the performance efficiencies of SPDK into QEMU/KVM virtualization environments. Compared with existing kernel based vhost solutions, SPDK vhost target provides up to 10x better performance and/or efficiency while enabling significantly lower latency when used with Intel Optane media. Using both SPDK based NVMe-oF target and host, the round trip latency of single I/O can be reduced to 50% compared the total solution provided by Linux kernel. This session covers the performance of SPDK vhost target, design principles for CPU efficiency, usage models and future plans.

Linux gained the first publicly release driver for the then new NVM Express standard in early 2011. It went through a lot of changes since then, including the move the new blk-mq block driver infrastructure, the addition of NVMe over Fabrics support including the split of the driver

into a common core and transport drivers and the addition of lots of feature since then.

This talk starts by explaining the historic development of the Linux NVMe driver including it’s influence on common Linux code and then presents the current new features and developments including power management, host memory buffer support, adaptive I/O polling support and the latest and greatest in Fabrics including multipathing support.

This talk will explore new capabilities that are proposed to be added to SMB3 for supporting emerging scenarios like containers, direct-access filesystem (DAX ) and large scale-out clusters with affinitized storage.

Containerized workloads accessing data hosted on a remote share typically authenticate to the remote resource using the identity of the container or a pre-plumbed credential setup by an administrator. We explore “identity tunneling” extensions to the protocol to allow applications to tunnel their identity to the server on top of an existing authenticated SMB session.

Direct access storage (Storage Class Memory (SCM) /Persistent Memory (PM)) is now being deployed in more and more scenarios where low-latency IO is required. SMBDirect/RDMA provides a mechanism for clients to directly access DAX storage on a server. We will look at various approaches to accessing DAX storage – first via the existing SMB3 protocol and potential enhancements to mostly bypass the software stack on the client and server.

Lastly in the context of a large scale-out cluster, we’ll take a look at enhancements to the SMB3 protocol to automatically direct the cluster-node hosting the data need by the client. This complements some of the functionality provided by the Witness protocol – and is a step towards scaling out data access via the SMB3 protocol.

While the “perfect” workload to test an array for a customer is the workload or combination that will run against the array in production, enterprises and vendors benefit greatly from a workload approach that more accurately models a production workload to be executed against an array. Enterprises benefit by seeing the characteristics of their own workload or combination, while vendors benefit by being able to scale emulated workloads to array limits and better able to deal with performance issues that occur only after an array is released.

Spatial locality, temporal locality emulating application “burstiness” ensure no array is unrealistically penalized nor given a “free pass” because a test does not reflect the application behavior that will be seen in production.

This is a non-trivial exercise. New approaches use storage controller performance measurement or wire data to derive application workload models that make it possible to test how an application or application combination affects array performance.

Persistent memory NVDIMMs create security challenges, some of which are familiar while others are new. The NVM Programming TWG has been working on a security threat model for Persistent Memory that exposes gaps where solutions need to evolve beyond those that met the needs of hard disks and SSD’s. This session describes the current work in progress of the TWG that will appear in a future white paper.

Learning Objectives: 1)Learn what how persistent memory security solutions may differ from hard disk and SSD solutions; 2)Learn how multi-tenancy in a cloud datacenter relates to Persistent Memory security features; 3)Show how protection of data at rest can facilitate secure reuse of NVDIMMs.

The SNIA NVM Programming model enables applications to consume emerging persistent memory technologies through step-wise evolution to greater and greater value. Starting with an overview of the recently released revision of the NVM programming model specification version 1.2, this session summarizes the changes and the continuing work of the NVM programming TWG in areas of high availability and security. We take an application view of ongoing technical innovation in a persistent memory ecosystem.

Learning Objectives: 1) Learn about the exciting things happening in the SNIA NVM programming TWG; 2)Get an overview of several key topics of the SNIA NVM Programming Model; 3)Learn about the resources available to help developers plan and implement persistent memory aware software.

NVMe is one of the most interesting new developments to happen to storage in the past several years, and NVMe over Fabrics extends these capabilities over a Storage Area Network. Given that 80% of all existing Flash storage solutions deployed are interconnected with Fibre Channel (FC), many questions have arisen about what it is, how it works, and why someone might want to consider using Fibre Channel for NVMe-based solutions.

Learning Objectives: 1)How does Fibre Channel and NVMe work together?; 2)How is NVMe over Fabrics different from “traditional” Fibre Channel?; 3)What changes do I have to make to my Fibre Channel environment in order to get NVMe over Fabrics to work?; 4)What would an NVMe over Fibre Channel (FC-NVMe) architecture look like?; 5)What advantages would I get using Fibre Channel in an NVMe solution?

The industry needs a protocol that provides efficient storage operations for both data centers and hyperscale applications. Data centers are willing to pay more for more complex interfaces that provide reliable data response times, while Hyperscalers want the lowest cost and greatest flexibility to optimize their cost/performance ratios. Two paths are under consideration to provide deterministic read latency. One is I/O determinism in which the host controls the timing of reads vs. writes to storage elements specified by the controller. This approach requires complex controller firmware leading to highly capable but possibly more expensive controllers. Data centers find this to be easy to install and manage. The other path is Open Channel (Open Fabrics Alliance) where the controller provides information about the physical characteristics of the storage device (e.g., channel and die layout) and the host determines the physical location that data is stored on the medium. Hyperscalers believe this allows them to program their algorithms for writes and reads more effectively to prevent outlier read latencies, as they control all of the knobs on the device. There is also a perception that these SSDs should be less expensive. This configuration requires more initial effort by systems software and continued re-writing of code to keep up with changing SSD technologies that impact what criteria need to be controlled to provide optimal performance.

The implementation of SMB3 is a broad and important set of topics on the Samba roadmap. After a longer period of preparations, the first and the most generally useful of the advanced SMB3 features has recently arrived in Samba: Multi-Channel. This presentation will explain Samba's implementation of Multi-Channel, especially covering the challenges that had to be solved for integration with Samba's traditional clustering with CTDB, which is invisible to the SMB clients and hence quite different from the clustering built into SMB3. Afterwards an outlook will be given on other areas of active development like persistent file handles, RDMA, and scale-out SMB clustering, reporting on status and challenges.