Large number of Unknown Volumes detected

If you see event errors titled ‘Syncing locally created volumes’ and messages like ‘Found the following volumes, but skipped due to missing local service:’, this means that you have containers being created with volumes that are not defined in ComputeStacks.

When the container is created with a VOLUME defined in the Dockerfile, but ComputeStacks isn’t aware of it, Docker will automatically create that volume. If that volume is the parent or child of a volume defined in ComputeStacks, then ComputeStacks will skip importing it and create another error

Fatal error importing volume <volume-id>
Container path is already in use.

To learn more how to resolve that issue, please see our topic on that.

Then, when ComputeStacks rebuilds the container or moves it, the volume created by Docker will be orphaned, generating the list you’re seeing.

Once the volume is no longer associated with a container, you can safely manually remove them from the node. ComputeStacks takes a very conservative view of customer data and will not automatically remove these. Instead, it creates this report and expects a human to intervene and both a) clean it up, and b) understand why it’s happening and resolve the original issue.

Note: If the volume is in use, docker won’t let you delete it.