IRIX Root Directories

The main directories of the root file system (/) are as follows:

/: Contains hardware-specific files and files required to start the system.
bin: Contains publicly executable commands. (Some are root-only.)
debug: Provides a link to /proc.
dev: Contains special files that define all of the devices on the system.
etc: Contains administrative programs and tables.
lib: Contains public libraries.
lost+found: Used by fsck(1M) to save disconnected files and directories.
proc: Provides an interface to running processes that may be used by debuggers such as dbx(1).
tmp: Used for temporary files.
usr: Used to mount the /usr file system and for files that are the same from system to system. These files are not writable.
var: Used for files that are specific to each system. There is typically a symbolic link to /usr for each file in /var.