I am trying to use LXD with nested Docker for applications that run computations on the GPU (e.g. deep learning with tensorflow).
On the host system (Ubuntu 18.04 Server) only LXD and the GPU drivers (
nvidia-driver-430) are installed. The usual Ubuntu 18.04 image is used for the LXD container with
security.nesting true and the GPU was added to the container via
lxc config device add docker gpu gpu, the option
nvidia.runtime was not set. I installed
nvidia-driver-430 in the LXD container and also the nvidia-container-toolkit as well as Docker. In the LXD container
docker run hello-world work fine.
When trying to use the GPUs with a Docker container, I get the following error message:
ubuntu@docker:~$ docker run --gpus all nvidia/cuda:10.1-base nvidia-smi Unable to find image 'nvidia/cuda:10.1-base' locally 10.1-base: Pulling from nvidia/cuda 35c102085707: Pull complete 251f5509d51d: Pull complete 8e829fe70a46: Pull complete 6001e1789921: Pull complete 9f0a21d58e5d: Pull complete 47b91ac70c27: Pull complete a0529eb74f28: Pull complete Digest: sha256:ed16350d934ba7b4cef27cbd5e3e1cdeae9d89a0aedd3f66972bf4377f76ca09 Status: Downloaded newer image for nvidia/cuda:10.1-base docker: Error response from daemon: OCI runtime create failed: container_linux.go:345: starting container process caused "process_linux.go:430: container init caused \"process_linux.go:413: running prestart hook 0 caused \\\"error running hook: exit status 1, stdout: , stderr: nvidia-container-cli: mount error: write error: /sys/fs/cgroup/devices/docker/8a1bfba9d762f426f8c59a7b44f969fc4ce3b49d386e5fb3305c3ae3d0cf35fb/devices.allow: operation not permitted\\\\n\\\"\"": unknown. ERRO error waiting for container: context canceled
There seem to be some kind of permission problem writing to
/sys/fs/cgroup/devices/docker/. I also tried to examine the problem using
strace but couldn’t find any clue. I verified that the setup should work in general by using the option
security.privileged true for the LXD container. For a privileged LXD container everything works fine and
nvidia-smi is executed correctly within the Docker container showing the GPU.
However, for my use case it is not possible to use a privileged LXD container. Has anyone faced the same (or a similar) problem? Do you have an idea how to debug this problem further?
Some background information: I am using a GeForce GTX 1080 Ti (using
nvidia-driver-430) on Ubuntu Server 18.04.3, with the following versions of LXD and docker.
LXD version (on host):
$ lxc version Client version: 3.17 Server version: 3.17
Docker version (in LXD container)
$ docker version Client: Docker Engine - Community Version: 19.03.2 API version: 1.40 Go version: go1.12.8 Git commit: 6a30dfc Built: Thu Aug 29 05:29:11 2019 OS/Arch: linux/amd64 Experimental: false Server: Docker Engine - Community Engine: Version: 19.03.2 API version: 1.40 (minimum version 1.12) Go version: go1.12.8 Git commit: 6a30dfc Built: Thu Aug 29 05:27:45 2019 OS/Arch: linux/amd64 Experimental: false containerd: Version: 1.2.6 GitCommit: 894b81a4b802e4eb2a91d1ce216b8817763c29fb runc: Version: 1.0.0-rc8 GitCommit: 425e105d5a03fabd737a126ad93d62a9eeede87f docker-init: Version: 0.18.0 GitCommit: fec3683