I've been struggling to find a straightforward method for backing up and restoring Docker volumes. While Docker has easy Save/Export options for images and containers, it seems like there's no easy way to do the same for volumes, which hold the crucial data I need. Tools like Portainer, which are supposed to simplify Docker management for beginners, seem to lack this capability as well. When I bring up this issue in forums or videos, people often say that I just need to understand Docker better because I can recreate images and containers with my compose file. However, I'm looking for a way to back up my data—like how I want to back up my personal files, not just reinstall Windows from an ISO. Can anyone help me understand how to easily back up and restore a Docker data volume, especially if I want to migrate to another host?
4 Answers
From what I've seen, a common approach to backup volumes is to use a bash command to save the volume as a tar file before exporting. I get where you're coming from—this can be a bit confusing! That's actually one of the reasons I prefer bind mounts because it makes it easier to copy files across systems.
The best approach is to use application-aware backups instead of just copying the volumes. Each app might require a different strategy for backup. For basic workloads like static sites, simply backing up the volume contents should work fine as long as you keep the permissions intact.
If you're looking for specific tools, consider trying out Backrest for a web UI option or Restic if you’re up for using the command line. These can help streamline the backup process.
Different applications need different backup strategies, which is why Docker doesn’t come with a one-size-fits-all backup solution. The idea behind Docker is to quickly spin up applications with specific configurations, which can usually be captured in compose files. So, the focus for backups should be on those files and the images. For user data, though, especially with databases, simply tarring up a running container isn’t enough to ensure data integrity. It's better to have an application-specific backup solution.
Thanks for clarifying! It helps to know that Docker approaches backups with the application in mind rather than providing an all-encompassing tool.