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:
- Source Code
- Unit Tests
- Advanced Build Options
- Shared libraries
- Hugepages and Device Binding
- Example Code
git clone https://github.com/spdk/spdk cd spdk git submodule update --init
The dependencies can be installed automatically by
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.
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.
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.
contains the base settings for the
configure script. This script generates a new
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
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:
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
CONFIG options may also be overridden on the
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:
./configure --with-dpdk=/path/to/dpdk/x86_64-native-linuxapp-gcc make
./configure --with-dpdk=/path/to/dpdk/x86_64-native-bsdapp-clang gmake
The options specified on the
make command line take precedence over the
mk/config.mk. This can be useful if you, for example, generate
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.
By default, the build of the SPDK yields static libraries against which
the SPDK applications and examples are linked.
--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
./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.
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 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.