Mounts

Why Linux Filesystem Tools Report Different Types

A disk partition can contain an ext4 filesystem while a process sees an overlay filesystem at /. Meanwhile, /proc/filesystems may list tmpfs and nfs, neither of which needs a local partition. These are not conflicting answers. They describe different parts of the Linux storage stack. The distinction matters when identifying a volume, investigating an unexpected mount, or checking which filesystem handles an application’s path. A filesystem signature on a device is not the same thing as a mounted filesystem in a process’s namespace.