Moving containers to new volume

[jacobtc]

I have been searching for a while now, and have found several different takes on this. I created my Docker containers a while back in Docker, and have since updated to Container Manager.
I have my shared "docker" folder on volume 1 and would like to move it to volume 2 as it is a NVME driver I just installed.
I don't have a clue about what a compose file is, I don't have any projects in the "Project" tab in Container Manager, which all the guides I've found expect.

I tried changing the volume location as shown in this video:

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

View: https://www.youtube.com/watch?v=YR2A0NMfgas
But apparently this now requires me to uninstall Container Manager? The video shows him just stopping it, and it works.

I really don't want to screw up my four containers, so I don't want to be hasty about this.

 

[one-eyed-king]

I haven't watched the video.

A compose file is just another way to describe the configuration of docker resource configurations, like containers, volumes, and networks. There are ways to generate compose files for existing containers, but they will require you to be comfortable using ssh connections to your docker host (=your nas) and work with terminal commands. Once you created a compose file per container, you could follow the tutorials you found. If you feel comfortable, I can share how it's done.

Are you confident, that each of your container maps a host path into the expected container path to store persistent data outside the container files system? If not, this should be the first thing to take care of. Otherwise, you will lose data permanently if you remove and recreate your container.

Note: a container is meant to be disposable/ephemeral by design. It is common practice to delete and recreate containers, e.g. when a new version of the image exists, and you want to create a new container based on the new image (=that's how version updates are done in the docker world).

Generally, every Syno package should allow changing the volume it is installed on. If you change it for the Container Manger, it will move the data to the selected volume. Though, I am not sure, if the metadata of existing containers is also updated when docker's data-root folder is moved.

 

[dimfil]

If I understand correctly ( I didn't have the time to watch full video) these instructions are about how to move persistent storage to another volume. That is fine, but I would suggest to move complete Container Manager to the faster volume. That means that that you would have to uninstall Container Manager then install it again on Volume2.
Now, to my opinion there are a couple of ways you could do that with minimal or no effect on your existing containers and has to do on how you created them on the first place: did you use app's GUI, docker commands or docker compose?
It would help to tell us which containers you have and how you created them so we may have to propose a better way to create them again.
In any case, I would suggest to spend some time learning the basics of docker compose files (named as projects in Container Manager) because it is a much more easier and "cleaner" way to create and manage your containers to my opinion.

 

[one-eyed-king]

@dimfil's responds makes me think that I remembered this wrong:

Generally, every Syno package should allow changing the volume it is installed on. If you change it for the Container Manger, it will move the data to the selected volume.

Probably I confused it with moving shares. Its been a while since I migrated to UGREEN metal with TrueNAS on top. I do run the required containers there now.

(named as projects in Container Manager)

Actually, that's the official docker terminology for the resulting deployment of a compose file.

 

[dimfil]

@dimfil's responds makes me think that I remembered this wrong:

Probably I confused it with moving shares. Its been a while since I migrated to UGREEN metal with TrueNAS on top. I do run the required containers there now.

Me too have moved to a Proxmox VM for docker needs. At the moment I use my DS923+ only for storage purposes via NFS and SMB.

Actually, that's the official docker terminology for the resulting deployment of a compose file.

Great to know!
To be honest, I see different terminology on this (stacks, projects etc) but I never bothered finding what is the official term!