The Storage Performance Development Kit (SPDK) provides a set of tools and libraries for writing high performance, scalable, user-mode storage applications. It achieves high performance by moving all of the necessary drivers into userspace and operating in a polled mode instead of relying on interrupts, which avoids kernel context switches and eliminates interrupt handling overhead.

The bedrock of SPDK is a user space, polled-mode, asynchronous, lockless NVMe driver. This provides zero-copy, highly parallel access directly to an SSD from a user space application. The driver is written as a C library with a single public header. Similarly, SPDK provides a user space driver for the I/OAT DMA engine present on many Intel Xeon-based platforms with all of the same properties as the NVMe driver.

SPDK also provides NVMe-oF and iSCSI servers built on top of these user space drivers that are capable of serving disks over the network. The standard Linux kernel iSCSI and NVMe-oF initiator can be used (or the Windows iSCSI initiator even) to connect clients to the servers. These servers can be up to an order of magnitude more CPU efficient than other implementations.

SPDK is an open source, BSD licensed set of C libraries and executables hosted on GitHub. All new development is done on the master branch and stable releases are created quarterly. Contributors and users are welcome to submit patches, file issues, and ask questions on our mailing list.

News

SPDK 16.12 Release

By Jim Harris and Jonathan Stern

Today we have released SPDK 16.12. This release contains the following major additions since our last release:

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Announcing the SPDK NVMf Target

By Jonathan Stern

Much has already been said about NVMe over Fabrics. It was first publically demonstrated in 2014 and the 1.0 specification is finally complete. In essence, NVMe over Fabrics (NVMf) is the NVM Express* (NVMe) block protocol tunneled through an RDMA fabric, and it has enormous potential to enable the next generation of datacenter storage development. To support broad adoption of NVMf, the Storage Performance Development Kit (SPDK) has created a reference user-space NVMf target implementation for Linux, released for community involvement via GitHub under BSD license. In parallel, community-based Linux* kernel efforts have created both a host and a target under GPL license. All three of these implementations are now released with the final 1.0 specification as of June 8, 2016.

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Why SPDK?

By Jonathan Stern

Solid-state storage media is in the process of taking over the data center. Current-generation flash storage enjoys significant advantages in performance, power consumption, and rack density over rotational media. These advantages will continue to grow as next-generation media enter the marketplace.

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