How to Backup Restore or Migrate data volumes in a docker container

Question

What is the procedure for backup,restore data volumes in docker? Could you please explain?

Answer 1

Steps to Backup a container

1)      Launch a new container and mount the volume from the dbstore container

2)      Mount a local host directory as /backup

3)      Pass a command that tars the contents of the dbdata volume to a backup.tar file inside our /backup directory.

$ docker run --rm --volumes-from dbstore -v $(pwd):/backup ubuntu tar cvf /backup/backup.tar /dbdata

Restore container from backup

With the backup just created, you can restore it to the same container, or another that you made elsewhere.

For example, create a new container named dbstore2:

$ docker run -v /dbdata --name dbstore2 ubuntu /bin/bash 

Then un-tar the backup file in the new container`s data volume:

$ docker run --rm --volumes-from dbstore2 -v $(pwd):/backup ubuntu bash -c "cd /dbdata && tar xvf /backup/backup.tar --strip 1"

Comments

So there aren't any issues with live containers? I saw that databases should be backup with replication but isn't there the same issues with other containers? Shouldn't they be stopped before backup? If so how should it be done? I really lost there, i've looked it up for 2 days and i don't have any clue on how to do it properly...

About container backup: https://blog.linuxserver.io/2019/10/01/updating-and-backing-up-docker-containers-with-version-control/ but not much on data backup: "App data can be backed up via tar and stored in an archive file on the same machine or a remote machine.".

Any clue would be highly appreciated :)

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I am not clear with your doubt. But if you are looking for backup of your data, then create one persistent volume and mount it. Now you can transfer this volume in any other container.