Restoring a backup

[Sabst]

To restore backup files (e.g. config, data, themes directories), I copy the files into the running container (let's leave the DB aside for now).
This unfortunately fails due to the way those directories are mounted (I get errors about a read-only or busy filesystem).
How is this supposed to be done in that environment?
Thanks

[Sabst]

I do not think the backup/restore of those deployments have been considered.
I worked around the problem by relying on post-renderer/kustomize and still have to see how reliable this is...