3c22b8e41b
Starting with this patch it is possible to remove a
snapshot if there is only a one clone created from it.
In such case snapshot can be removed without any data
copying. This is achieved with following steps (case
with only one clone):
1. Open snapshot (Snapshot1) that shall be removed
2. Check if the Snapshot1 has no more than 1 clone (Clone1)
3. Remove Clone1 entry from Snapshot1
4. If the Snapshot1 has a parent snapshot (Snapshot2):
4a. Add Clone1 entry to the Snapshot2 clones list
4b. Remove Snapshot1 entry from Snapshot2 clones list
5. Open Clone1 blob
6. Freeze I/O operations on Clone1
7. Temporarily override md_ro flag for Snapshot1 and Clone1
for MD modification
8. Merge Snapshot1 and Clone1 clusters maps into Clone1
clusters map
9a. If Snapshot2 is present switch parent ID and backing
bs_dev on Clone1
9b. If Snapshot2 is not present set parent ID to
SPDK_BLOBID_INVALID and backing bs_dev to zeroes_dev
10. Sync MD on Clone1
11. Sync MD on Snapshot1
12. Restore MD flags for Clone1 and Snapshot1
13. Unfreeze I/O on Clone1
14. Close Clone1 blob
15. Remove Snapshot1
Signed-off-by: Maciej Szwed <maciej.szwed@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/445576 (master)
(cherry picked from commit 622127d7e10b0f383c3f2334a8900272c1bbf9b2)
Change-Id: I800724b981af894e01e1912d0077c5b34a2ae634
Signed-off-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/458464
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
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.
./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