Mountbased

Mountbased is a term used in computing to describe strategies that create isolated or portable execution environments primarily through filesystem mounts. In a mountbased approach, functionality and data are not copied; instead, a filesystem view is assembled by mounting existing directories, disk images, or virtual filesystems at specific mount points. This enables processes to operate within a controlled perspective of the filesystem, often with restricted access to the host system.

Mechanisms commonly associated with mountbased environments include bind mounts, mount namespaces, and layered or union filesystems such as overlayfs. Bind mounting allows a directory to be presented at multiple locations. Overlay or union mounts combine a writable layer with one or more read-only layers to produce a composite filesystem.

Use cases include sandboxing untrusted code, building reproducible development environments, and running maintenance or recovery tools without altering the host filesystem. Mountbased setups are central to many containerized workflows, chroot-like environments, and portable runtimes, where the root filesystem can be mounted from an image or directory and then executed from that vantage point.

Implementation notes: creating a mountbased environment typically requires appropriate privileges. It may involve creating a new mount namespace, mounting a root image or directory, and then launching processes within that mount context. Cleanup usually involves unmounting the view and terminating the namespace.

Security considerations include boundary control between mounts, proper unmounting to avoid leaks, and minimizing the risk of privilege escalation via mount operations.