Ceph NVMe over Fabrics (NVMe-oF) Gateway

This project provides block storage on top of Ceph for platforms (e.g.: VMWare) without native Ceph support (RBD), replacing existing approaches (iSCSI) with a newer and more versatile standard (NVMe-oF).

Essentially, it allows to export existing RBD images as NVMe-oF namespaces. The creation and management of RBD images is not within the scope of this component.

Installation

Requirements

• Linux-based system with at least 16 GB of available RAM. Fedora 37 is recommended.

• SELinux in permissive mode:

  sed -i s/^SELINUX=.*$/SELINUX=permissive/ /etc/selinux/config
  setenforce 0

Dependencies

• moby-engine (docker-engine) (v20.10) and docker-compose (v1.29). These versions are just indicative
• make (only needed to launch docker-compose commands).

To install these dependencies in Fedora:

sudo dnf install -y make moby-engine docker-compose

Some post-installation steps are required to use docker with regular users:

sudo groupadd docker
sudo usermod -aG docker $USER

Steps

To launch a containerized environment with a Ceph cluster and a NVMe-oF gateway (this is not the prescribed deployment for production purposes, but for testing and development tasks alone):

1. Get this repo:

   git clone https://github.com/ceph/ceph-nvmeof.git
   cd ceph-nvmeof
   git submodule update --init --recursive

2. Configure the environment (basically to allocate huge-pages, which requires entering the user password):

   make setup

3. Download the container images:

   make pull

4. Deploy the containers locally:

   make up

5. Check that the deployment is up and running:

   $ make ps
   
       Name                    Command                  State                               Ports
   -----------------------------------------------------------------------------------------------------------------------
   ceph              sh -c ./vstart.sh --new $V ...   Up (healthy)   5000/tcp, 6789/tcp, 6800/tcp, 6801/tcp, 6802/tcp,
                                                                     6803/tcp, 6804/tcp, 6805/tcp, 80/tcp
   nvmeof_nvmeof_1   python3 -m control -c ceph ...   Up             0.0.0.0:4420->4420/tcp,:::4420->4420/tcp,
                                                                     0.0.0.0:5500->5500/tcp,:::5500->5500/tcp,
                                                                     0.0.0.0:8009->8009/tcp,:::8009->8009/tcp

6. The environment is ready to provide block storage on Ceph via NVMe-oF.

Usage Demo

Configuring the NVMe-oF Gateway

The following command executes all the steps required to set up the NVMe-oF environment:

$ make demo
docker-compose  exec  ceph bash -c "rbd -p rbd info demo_image || rbd -p rbd create demo_image --size 10M"
rbd: error opening image demo_image: (2) No such file or directory
docker-compose  run --rm nvmeof-cli --server-address 192.168.13.3 --server-port 5500 subsystem add --subsystem "nqn.2016-06.io.spdk:cnode1"
Adding subsystem nqn.2016-06.io.spdk:cnode1: Successful
docker-compose  run --rm nvmeof-cli --server-address 192.168.13.3 --server-port 5500 namespace add --subsystem "nqn.2016-06.io.spdk:cnode1" --rbd-pool rbd --rbd-image demo_image
Adding namespace 1 to nqn.2016-06.io.spdk:cnode1, load balancing group 1: Successful
docker-compose  run --rm nvmeof-cli --server-address 192.168.13.3 --server-port 5500 listener add --subsystem "nqn.2016-06.io.spdk:cnode1" --host-name fbca1a3d3ed8 --traddr 192.168.13.3 --trsvcid 4420
Adding listener 192.168.13.3:4420 to nqn.2016-06.io.spdk:cnode1: Successful
docker-compose  run --rm nvmeof-cli --server-address 2001:db8::3 --server-port 5500 listener add --subsystem "nqn.2016-06.io.spdk:cnode1" --host-name fbca1a3d3ed8 --traddr 2001:db8::3 --trsvcid 4420 --adrfam IPV6
Adding listener [2001:db8::3]:4420 to nqn.2016-06.io.spdk:cnode1: Successful
docker-compose  run --rm nvmeof-cli --server-address 192.168.13.3 --server-port 5500 host add --subsystem "nqn.2016-06.io.spdk:cnode1" --host "*"
Allowing any host for nqn.2016-06.io.spdk:cnode1: Successful

Manual Steps

The same configuration can also be manually run:

1. First of all, let's create the cephnvmf shortcut to interact with the NVMe-oF gateway:

   eval $(make alias)

2. In order to start working with the NVMe-oF gateway, we need to create an RBD image first (demo_image in the rbd pool):

   make rbd

3. Create a subsystem:

   cephnvmf subsystem add --subsystem nqn.2016-06.io.spdk:cnode1

4. Add a namespace:

   cephnvmf namespace add --subsystem nqn.2016-06.io.spdk:cnode1 --rbd-pool rbd --rbd-image demo_image

5. Create a listener so that NVMe initiators can connect to:

   cephnvmf listener add ---subsystem nqn.2016-06.io.spdk:cnode1 --host-name host_name -a gateway_addr -s 4420

6. Define which hosts can connect:

   cephnvmf host add --subsystem nqn.2016-06.io.spdk:cnode1 --host "*"

Mounting the NVMe-oF volume

Once the NVMe-oF target is

1. Install requisite packages:

   sudo dnf install nvme-cli
   sudo modprobe nvme-fabrics

2. Ensure that the listener is reachable from the NVMe-oF initiator:

   $ sudo nvme discover -t tcp -a 192.168.13.3 -s 4420
   
   Discovery Log Number of Records 1, Generation counter 2
   =====Discovery Log Entry 0======
   trtype:  tcp
   adrfam:  ipv4
   subtype: nvme subsystem
   treq:    not required
   portid:  0
   trsvcid: 4420
   subnqn:  nqn.2016-06.io.spdk:cnode1
   traddr:  192.168.13.3
   eflags:  not specified
   sectype: none

3. Connect to desired subsystem:

   sudo nvme connect -t tcp --traddr 192.168.13.3 -s 4420 -n nqn.2016-06.io.spdk:cnode1

4. List the available NVMe targets:

   $ sudo nvme list
   Node                  Generic               SN                   Model                                    Namespace Usage                      Format           FW Rev
   --------------------- --------------------- -------------------- ---------------------------------------- --------- -------------------------- ---------------- --------
   /dev/nvme1n1          /dev/ng1n1            Ceph00000000000001   Ceph bdev Controller                     1          10,49  MB /  10,49  MB      4 KiB +  0 B   23.01
   ...

5. Create a filesystem on the desired target:

   $  sudo mkfs /dev/nvme1n1
   mke2fs 1.46.5 (30-Dec-2021)
   Discarding device blocks: done
   Creating filesystem with 2560 4k blocks and 2560 inodes
   
   Allocating group tables: done
   Writing inode tables: done
   Writing superblocks and filesystem accounting information: done

6. Mount and use the storage volume

   $ mkdir /mnt/nvmeof
   $ sudo mount /dev/nvme1n1 /mnt/nvmeof
   
   $ ls /mnt/nvmeof
   lost+found
   
   $ sudo bash -c "echo Hello NVMe-oF > /mnt/nvmeof/hello.txt"
   
   $ cat /mnt/nvmeof/hello.txt
   Hello NVMe-oF

Start Discovery Service(Optional)

The discovery service can provide all the targets that the current user can access, and these target information is sourced from ceph omap. These targets may be running or just a record.

1. Start Discovery Service

   $ python3 -m control.discovery

2. To start discovery service container in docker-compose environment

   $ docker-compose up --detach discovery

3. Discover targets from discovery service. The default port is 8009.

   $ nvme discover -t tcp -a 192.168.13.3 -s 8009

Advanced

Configuration

This service comes with a pre-defined configuration that matches the most common use cases. For advanced configuration, please update the settings at the .env file. That file is automatically read by docker-compose. However, it's a perfectly valid bash source, so that it can also be used as:

source .env
echo $NVMEOF_VERSION...

mTLS Configuration for testing purposes

For testing purposes, self signed certificates and keys can be generated locally using OpenSSL.

For the server, generate credentials for server name 'my.server' in files called server.key and server.crt:

$ openssl req -x509 -newkey rsa:4096 -nodes -keyout server.key -out server.crt -days 3650 -subj '/CN=my.server'

For client:

$ openssl req -x509 -newkey rsa:4096 -nodes -keyout client.key -out client.crt -days 3650 -subj '/CN=client1'

Indicate the location of the keys and certificates in the config file:

[mtls]

server_key = ./server.key
client_key = ./client.key
server_cert = ./server.crt
client_cert = ./client.crt

Huge-Pages

DPDK requires hugepages to be set up:

sh -c 'echo 4096 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages'

This is automatically done in the make setup step. The amount of hugepages can be configured with make setup HUGEPAGES=512.

Development

Set-up

The development environment relies on containers (specifically docker-compose) for building and running the components. This has the benefit that, besides docker and docker-compose, no more dependencies need to be installed in the host environment.

Once the GitHub repo has been cloned, remember to initialize its git submodules (spdk, which in turn depends on other submodules):

git submodule update --init --recursive

For building, SELinux might cause issues, so it's better to set it to permissive mode:

# Change it for the running session
sudo setenforce 0

# Persist the change across boots
sudo sed -i -E 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

Building

Containers

To avoid having to deal with docker-compose commands, this provides a Makefile that wraps those as regular make targets:

To build the container images from the local sources:

make build

The resulting images should be like these:

$ docker images
REPOSITORY                    TAG       IMAGE ID       CREATED         SIZE
quay.io/ceph/nvmeof-cli       0.0.1     8277cd0cce2d   7 minutes ago   995MB
quay.io/ceph/nvmeof           0.0.1     34d7230dcce8   7 minutes ago   439MB
quay.io/ceph/vstart-cluster   17.2.6    cb2560975055   8 minutes ago   1.27GB
quay.io/ceph/spdk             23.01     929e22e22ffd   8 minutes ago   342MB

• spdk is an intermediate image that contains an RPM-based installation of spdk with rbd support enabled.
• nvmeof is built from the spdk container by installing the Python package.
• nvmeof-cli provides a containerized environment to run CLI commands that manage the nvmeof service via gRPC.
• ceph is a sandboxed (vstart-based) Ceph cluster for testing purposes.

For building a specific service:

make build SVC=nvmeof

Stand-alone Packages

To generate independent RPM and Python wheel packages:

make export-rpms export-python
RPMs exported to:
/tmp/rpm/x86_64/spdk-libs-23.01-0.x86_64.rpm
/tmp/rpm/x86_64/spdk-devel-23.01-0.x86_64.rpm
/tmp/rpm/x86_64/spdk-23.01-0.x86_64.rpm
Python wheel exported to:
/tmp/ceph_nvmeof-0.0.1-py3-none-any.whl

Development containers

To avoid having to re-build container on every code change, developer friendly containers are provided:

docker-compose up nvmeof-devel

Devel containers provide the same base layer as the production containers but with the source code mounted at run-time.

Adding, removing or updating Python dependencies

Python dependencies are specified in the file pyproject.toml (PEP-621), specifically under the dependencies list.

After modifying it, the dependency lockfile (pdm.lock) needs to be updated accordingly (otherwise container image builds will fail):

make update-lockfile
git add pdm.lock

Help

To obtain a detailed list of make targets, run make help:

Makefile to build and deploy the Ceph NVMe-oF Gateway

Usage:
    make [target] [target] ... OPTION=value ...

Targets:

  Basic targets:
      clean           Clean-up environment
      export-python   Build Ceph NVMe-oF Gateway Python package and copy it to /tmp
      export-rpms     Build SPDK RPMs and copy them to $(EXPORT_DIR)/rpm
      setup           Configure huge-pages (requires sudo/root password)
      up              Services
      update-lockfile Update dependencies in lockfile (pdm.lock)

    Options:
      EXPORT_DIR      Directory to export packages (RPM and Python wheel) (Default: /tmp)
      up: SVC         Services (Default: nvmeof)

  Deployment commands (docker-compose):
      build           Build SVC images
      down            Shut down deployment
      events          Receive real-time events from containers
      exec            Run command inside an existing container
      images          List images
      logs            View SVC logs
      pause           Pause running deployment
      port            Print public port for a port binding
      ps              Display status of SVC containers
      pull            Download SVC images
      push            Push nvmeof and nvmeof-cli containers images to quay.io registries
      restart         Restart SVC
      run             Run command CMD inside SVC containers
      shell           Exec shell inside running SVC containers
      stop            Stop SVC
      top             Display running processes in SVC containers
      unpause         Resume paused deployment
      up              Launch services

    Options:
      CMD             Command to run with run/exec targets (Default: )
      DOCKER_COMPOSE  Docker-compose command (Default: docker-compose)
      OPTS            Docker-compose subcommand options (Default: )
      SCALE           Number of instances (Default: 1)
      SVC             Docker-compose services (Default: )

  Demo:
      demo            Expose RBD_IMAGE_NAME as NVMe-oF target

  Miscellaneous:
      alias           Print bash alias command for the nvmeof-cli. Usage: "eval $(make alias)"

Targets may accept options: make run SVC=nvme OPTS=--entrypoint=bash.

Troubleshooting

Contributing and Support

See CONTRIBUTING.md.

Code of Conduct

See Ceph's Code of Conduct.

License

See LICENSE.