Storage Performance Development Kit

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 development kit currently includes:

• NVMe driver
• I/OAT (DMA engine) driver
• NVMe over Fabrics target
• iSCSI target
• vhost target
• Virtio-SCSI driver

In this readme

• Documentation
• Prerequisites
• Source Code
• Build
• Unit Tests
• Vagrant
• Advanced Build Options
• Shared libraries
• Hugepages and Device Binding
• Example Code
• Contributing

Documentation

Doxygen API documentation is available, as
well as a Porting Guide for porting SPDK to different frameworks
and operating systems.

Source Code

git clone https://github.com/spdk/spdk
cd spdk
git submodule update --init

Prerequisites

The dependencies can be installed automatically by scripts/pkgdep.sh.
The scripts/pkgdep.sh script will automatically install the bare minimum
dependencies required to build SPDK.
Use --help to see information on installing dependencies for optional components

./scripts/pkgdep.sh

Build

Linux:

./configure
make

FreeBSD:
Note: Make sure you have the matching kernel source in /usr/src/ and
also note that CONFIG_COVERAGE option is not available right now
for FreeBSD builds.

./configure
gmake

Unit Tests

./test/unit/unittest.sh

You will see several error messages when running the unit tests, but they are
part of the test suite. The final message at the end of the script indicates
success or failure.

Vagrant

A Vagrant setup is also provided
to create a Linux VM with a virtual NVMe controller to get up and running
quickly. Currently this has only been tested on MacOS and Ubuntu 16.04.2 LTS
with the VirtualBox provider. The
VirtualBox Extension Pack must
also be installed in order to get the required NVMe support.

Details on the Vagrant setup can be found in the
SPDK Vagrant documentation.

Advanced Build Options

Optional components and other build-time configuration are controlled by
settings in the Makefile configuration file in the root of the repository. CONFIG
contains the base settings for the configure script. This script generates a new
file, mk/config.mk, that contains final build settings. For advanced configuration,
there are a number of additional options to configure that may be used, or
mk/config.mk can simply be created and edited by hand. A description of all
possible options is located in CONFIG.

Boolean (on/off) options are configured with a 'y' (yes) or 'n' (no). For
example, this line of CONFIG controls whether the optional RDMA (libibverbs)
support is enabled:

CONFIG_RDMA?=n

To enable RDMA, this line may be added to mk/config.mk with a 'y' instead of
'n'. For the majority of options this can be done using the configure script.
For example:

./configure --with-rdma

Additionally, CONFIG options may also be overridden on the make command
line:

make CONFIG_RDMA=y

Users may wish to use a version of DPDK different from the submodule included
in the SPDK repository. Note, this includes the ability to build not only
from DPDK sources, but also just with the includes and libraries
installed via the dpdk and dpdk-devel packages. To specify an alternate DPDK
installation, run configure with the --with-dpdk option. For example:

Linux:

./configure --with-dpdk=/path/to/dpdk/x86_64-native-linuxapp-gcc
make

FreeBSD:

./configure --with-dpdk=/path/to/dpdk/x86_64-native-bsdapp-clang
gmake

The options specified on the make command line take precedence over the
values in mk/config.mk. This can be useful if you, for example, generate
a mk/config.mk using the configure script and then have one or two
options (i.e. debug builds) that you wish to turn on and off frequently.

Shared libraries

By default, the build of the SPDK yields static libraries against which
the SPDK applications and examples are linked.
Configure option --with-shared provides the ability to produce SPDK shared
libraries, in addition to the default static ones. Use of this flag also
results in the SPDK executables linked to the shared versions of libraries.
SPDK shared libraries by default, are located in ./build/lib. This includes
the single SPDK shared lib encompassing all of the SPDK static libs
(libspdk.so) as well as individual SPDK shared libs corresponding to each
of the SPDK static ones.

In order to start a SPDK app linked with SPDK shared libraries, make sure
to do the following steps:

• run ldconfig specifying the directory containing SPDK shared libraries
• provide proper LD_LIBRARY_PATH

Linux:

./configure --with-shared
make
ldconfig -v -n ./build/lib
LD_LIBRARY_PATH=./build/lib/ ./app/spdk_tgt/spdk_tgt

Hugepages and Device Binding

Before running an SPDK application, some hugepages must be allocated and
any NVMe and I/OAT devices must be unbound from the native kernel drivers.
SPDK includes a script to automate this process on both Linux and FreeBSD.
This script should be run as root.

sudo scripts/setup.sh

Users may wish to configure a specific memory size. Below is an example of
configuring 8192MB memory.

sudo HUGEMEM=8192 scripts/setup.sh

Example Code

Example code is located in the examples directory. The examples are compiled
automatically as part of the build process. Simply call any of the examples
with no arguments to see the help output. You'll likely need to run the examples
as a privileged user (root) unless you've done additional configuration
to grant your user permission to allocate huge pages and map devices through
vfio.

Contributing

For additional details on how to get more involved in the community, including
contributing code and participating in discussions and other activities, please
refer to spdk.io