How to easily make a new container with all the programs and data duplicated or shared with the existing container

1

I use pytorch with a dataloader having multiple num_worker setting on the remote server with GPUs and got the error "DataLoader worker (pid xxx) is killed by signal: Bus error. ". I read Shm error in docker and now know that I need to build a new container with --shm-size option in docker run command. (That is one I use ). The question is that how to make all the programs and data existing in my current container available in anew container ? The volume is huge, like 500G. Or is there any other way to expand the shm size without making a new container ?

2

You don’t need to rebuild the container, but can use:

docker run -it --ipc=host your_docker_name

or specify --shm-size="" in the docker run command.

3

@prtbick Thank you for your reply. I am a beginner with docker and didn’t know that docker run can be applied to a built container. When I would like to use GPU on my server, which is better --ipc=host or --shm-size= ? Or Doesn’t it matter ?
Than you in advance.
Hiroshi

4

I threw the following command and got the error message ? What is wrong?

$ docker run -it --gpus all --shm-size=1g my_existing_container_name bash
Unable to find image ‘my_existing_container_name’ locally
docker: Error response from daemon: pull access denied for my_existing_container_name, repository does not exist or may require ‘docker login’: denied: requested access to the resource is denied.
See ‘docker run --help’.

5

I’m using --ipc=host, while others prefer --shm-size so you might stick to what works for you.

It seems that my_exsisting_container_name is not recognized. Are you sure you’ve tagged the container with this name?
During your build you can create a tag for the container using:

docker build -t container_name .
6

Thank you for your comment on --ipc=host or --shm-size.
Regarding your saying
$ docker build -t container_name,
I am confused. By dockerfile docker build command document, is container_name an image instead of a container ?

Let me explain the history leading up to here.

Firstly, my administrator built an image, original_image, from nvidia hub for us and I made my_existing_container_name from that image by
$ docker run -it --gpus all --name my_existing_container_name original_image bash

Then I worked on this container, creating many new applications and data for a while and then found that the container needs more shared memory to run a specific program I created. This initiates the question of this thread.

What I think I must do from now on is;

  1. To do docker commit to make a new image from the current my_existing_container_name by

docker commit my_existing_container_name myrepository:new_image

where myrepository and new_image are names which I can arbitrarily specify

  1. To do docker run for creating a my_new_container_name with a bigger shared memory from myrepository:new_image by

docker run --gpu all --ipc=host --name my_new_container_name myrepository:new_image bash

Are these right things to do ?

Thank you.

P.S. Even if the above are right things to do, I am another problem. The disk looks short of empty area to do commit because the my_existing_image_name gets too big. It says running up disk space. I am trying to increase empty disk space by deleting unnecessary files in the container or in the host.

7

You can commit your container, if you want to store your changes (e.g. your code).
I’m usually not saving the container and mount a folder to store my source code files, but your workflow might be different of course.

Otherwise, you could simply kill it and restart it with --ipc=host.

8

Thank you for your comments. I understood the way you do. You share directories and files on the host disk with the container you used by docker run -v xxxx option.

Thank you !.