Move docker containers to non-system drive

Needed to do this just now, and it mostly worked, though there is no "Click Install Docker" for my version of OMV6 (latest).

Only a "Reinstall Docker".

All the dockers are running and their paths point to the new drive which is good.

But now the mariadb docker is complaining it doesn't have permissions to /var/tmp

2024-05-08 [ERROR] mariadbd: Can't create/write to file '/var/tmp/ibXXXXXX' (Errcode: 13 "Permission denied")
2024-05-08 [ERROR] InnoDB: Unable to create temporary file; errno: 13
2024-05-08 [ERROR] mariadbd: Can't create/write to file '/var/tmp/ibXXXXXX' (Errcode: 13 "Permission denied")
2024-05-08 [ERROR] InnoDB: Unable to create temporary file; errno: 13

I manually chmod 777 /var/tmp from within the docker's bash terminal, and it fixed it for now, but from what other's have said this might break again next boot.

Any ideas?

Okay for anyone else needing to do this, if you follow those instructions you'll likely end up with a bunch of write permissions and lock file errors because cp -R wont preserve permissions.

So don't do this.

cp -R /var/lib/docker /srv/some-uuid/docker

but his instead.

sudo rsync -avzh /var/lib/docker /srv/some-uuid/docker

Hi I'm new and I know it's an old thread. Just recently I migrated my omv to the new device, minisforum ms-01. I migrated the whole server including docker and containers. For OS it was easy, just inserted disk where omv was installed, edited network via firstaid and for the disk with docker and container data I did next:

1. Created clonezilla live usb disk and booted into clonezilla

2. Cloned old docker disk to new Nvme drive

3. Inserted disk to new pc

4. Finished

There was absolutely nothing I had to do after that. Clonezilla even cloned disk with same uuid as before.

Hope this helps to someone.

Quote from KM0201

When it's finished go to the omv-extras docker plugin, and place the path in place of /var/lib/docker (ie, in the example above.. /srv/some-uuid/docker)

CLICK SAVE (this is important)

Once the new path is saved, Click Install Docker. This will not reinstall docker, it will simply update the docker configs with the new path.

Once it saves, giive it a moment and refresh and make sure docker shows "Installed and Running".

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Before I go ahead and do this, I am running OMV7 with everything up-to-date. I do not see an "Install Docker" option, only "Reinstall Docker". Are there updated steps in OMV7 with the latest Docker Compose plugin to move locations? I am looking to move my Docker install off the system disk and onto a separate NVMe drive. Thanks!

Apologies for replying to a Resolved post...

Quote from ryecoaaron

Reinstall = uninstall + install. If there is nothing to uninstall, it will just install. Since you have Docker installed, you want Reinstall anyway.

If you aren't using named volumes and don't mind downloading images again, I would just change the Docker storage path and click reinstall docker.

Appreciate the advice! I tried this, but ran into issues. I am thinking I might be missing a step, there might be one or more config files that need editing before/after the move, or perhaps there were permissions issues with the new Docker storage location:

1. Stopped Docker
2. Copied /var/lib/docker to the new location (/nvme/docker), using rsync command described above
3. Changed the Docker path to the new (nvme) path in the GUI, hitting Save.
4. Clicked on Reinstall Docker
5. "docker info | grep Root" showed my new nvme drive

Docker indicated it was running, but all my containers were Down and failed/errored whenever I tried to bring them back up manually. As I don't have enough experience with docker to interpret the error messages that popped up, I "panicked" and decided to revert.

I attempted to restore my old config (/var/lib/docker). It would not come back up at first, but then I remembered I had to edit the /etc/docker/daemon.json file, which was still referencing my nvme location.

So now I am back to where I started, but everything is at least working well. FYI I have no named volumes. Redownloading images is not a problem either!

OK - so I diligently attempted to follow all of the instructions above and in other areas of this Forum, alas to no avail - I was unable to move my docker storage location and have everything work afterwards.

However... in the end, success! Shockingly, from Google Gemini of all places. For posterity and in case it might help someone else in the future, I thought I would reproduce the steps here. The biggest difference I see here compared to previous advice, is that "systemctl stop docker" did not actually stop any of my containers. I had to individually stop them using the OMV GUI.

Forum admins - please feel free to delete this post if I inadvertently have provided bad advice. All I can say is that after following it, everything worked well afterwards, and my Docker storage is now independent of my system disk!

1. Prepare the Data Disk

Mount the disk: Ensure your data disk is properly mounted in OMV. You can do this through the OMV web interface under Storage > File Systems. Create a mount point for the disk, for example, /srv/dev-disk-by-id-yourdiskid. You could also just use an existing mounted file system.

Create a Docker directory: Inside the mount point, create a directory to store your Docker data. For example, /srv/dev-disk-by-id-yourdiskid/docker.

2. Stop Docker and Containers

Stop the Docker daemon: Use the following command in the OMV command line interface (CLI) to stop the Docker daemon:

systemctl stop docker

Stop all running containers: Make sure all your Docker containers are stopped before proceeding. You can use the following command to list running containers:

docker ps

And then stop them individually using:

docker stop <container_name_or_ID>

3. Copy Docker Data

Use rsync to copy data: It's essential to preserve file permissions and links when moving Docker data. The rsync command is ideal for this:

rsync -aHv /var/lib/docker /srv/dev-disk-by-id-yourdiskid

This command recursively copies all files and directories from the current Docker storage location (/var/lib/docker) to the new location on your data disk. The -a option ensures that permissions, ownership, and symbolic links are preserved. The -H option preserves hard links, and -v provides verbose output so you can see the progress.

4. Configure Docker to Use the New Location

OMV Web Interface: Go to the OMV web interface and navigate to Services > Compose > Settings.

Change Docker storage path: In the "Docker storage path" field, enter the new path to your Docker data directory on the data disk (e.g., /srv/dev-disk-by-id-yourdiskid/docker).

Save and Apply: Save the changes in the OMV web interface.

5. Restart Docker

Restart the Docker daemon:

systemctl start docker

Verify Docker: Check if Docker is running correctly and using the new storage location:

docker info | grep "Docker Root Dir"

6. Verify Functionality

Start your containers: Start your Docker containers and ensure they are functioning as expected. This can be done in the OMV GUI

Check container data: Verify that the data within your containers is accessible and consistent.

7. Clean Up (only after you are positive everything is working!)

Remove old Docker directory: Once you've confirmed everything is working correctly, you can safely remove the old Docker directory (/var/lib/docker) to free up space on your system drive.

Quote from Cap10Canuck

OK - so I diligently attempted to follow all of the instructions above and in other areas of this Forum, alas to no avail - I was unable to move my docker storage location and have everything work afterwards.

thanks for this. there was one issue though - the rsync command copies files over to /srv/dev-disk-by-id-yourdiskid/docker/docker

just change the rsync command to

rsync -aHv /var/lib/docker /srv/dev-disk-by-id-yourdiskid

or

rsync -aHv /var/lib/* /srv/dev-disk-by-id-yourdiskid/docker

works great after this