I've been searching everywhere, and I'm surprised that Docker doesn't provide a straightforward way to backup and restore volumes. While it's great that they have easy commands for saving/exporting images and containers, the lack of a simple backup solution for volumes (where all my important data is) is puzzling! Even GUI tools like Portainer don't seem to have this feature.
When I ask around, people often say, "Just recreate your images and containers if you have the compose file." But that's not what I'm looking for – I want a method to backup data like you would with personal files on a computer. If anyone can share insights on how to easily backup or move Docker data volumes, especially for migrating to another host, I would really appreciate it!
6 Answers
Docker doesn't have a one-size-fits-all backup feature because different applications require different solutions. The core purpose of Docker is to quickly deploy applications using configurations from compose files or other mounted configs. This can lead to confusion since it involves recreating the application rather than just backing up the data. When dealing with user data, especially with databases, simply creating a tar file of a running container might not guarantee data integrity. So, it's often better to have application-specific backup strategies instead of a generic tool.
That's why I prefer to use bind mounts – they're just easier for this kind of stuff.
Rather than just cloning volumes, aim for backup solutions that are aware of the applications they're supporting. Depending on what you're running, some applications like static web servers might only need the volume contents backed up directly, as long as you keep the right permissions.
Last time I checked, one way to backup Docker volumes is to use a bash command that saves them as a tar file. I totally get where you're coming from, as I've been on the hunt for backup solutions too. One option I like is using bind mounts; they're usually easier to copy around when needed.
Yeah, if we mention that, we'll probably get comments telling us we're doing it the wrong way instead of just providing a solid answer!
I appreciate your confusion; however, it's essential to think about why Docker isn’t equipped with specific backup tools. There are countless general backup solutions out there that can handle this without needing Docker-specific options. It's all about leveraging what's already available!
If a specific tool isn’t available, at least a tutorial or video on how to do it would be helpful. For instance, I use Macrium for backups, but I’m not sure which folders I should target.
Exactly! What kind of general tools are you suggesting, though?
If you're looking for options, you might want to check out backrest for a web UI setup or restic if you're comfortable using command-line tools.
Thanks for clarifying that! I understand now why a simple Backup/Restore option isn't standard in Docker.