The following list shows the filesystem supported by QNX:

In conclusion, most of these filesystems are resource managers that adopt a portion of the pathname space (called mountpoint) and provide filesystem services through the standar POSIX API (open(), close(), read(), etc.).

QNX provides a process, called pathname management that manages the pathname space and allows to support the POSIX semantics for device and file access, while making the use of those services optional for small embedded systems.

Some of these devices filesystems or mountpoints are: /dev/hd0, /dev/fd0, /dev/shmem, /dev/mem, /dev/zero, /dev/ser* (serial device), /dev/con* (simple console device), /dev/par* (parallel printer), /dev/pty* (pseudo console device) and so on.

In conclusion, when a process opens a file using the POSIX open() call, the library routine sends the pathname to procnto, where the pathname is compared against the prefix tree to determine which resource managers should be sent this message (This work is realized by pathname management thread).