System Administration Guide, Volume 1

Default Directories for root (/) and /usr File Systems

The /kernel directory contains only platform-independent objects, including a platform-independent kernel, genunix. See Table 40-3 for a description of /platform and /usr/platform, the platform-dependent directories.

The table below describes all the default directories contained in the root (/) file system.

Table 40-1 Default Directories in the root (/) File System




Root of the overall file system name space 


Primary location for special files 


Symbolic links to physical ap_ids 


Device files for uucp 


Block disk devices 


Frame buffer device files 


Logical volume management meta-disk devices 


File descriptors 


pty slave devices


Raw disk devices 


Raw tape devices 


Entry points for the STREAMS Administrative Driver 


Audio device and audio device control files 


Default swap device 


Serial devices 


Host-specific system administrative configuration files and databases 


Accounting configuration information 


Configuration information for cron


Defaults information for various programs 


Solstice Enterprise AgentsTM configuration files


Configuration information for shared file systems 


Dynamic Host Configuration Protocol (DHCP) configuration files 


Federated Naming Service and x.500 support files 


Binaries organized by file system types for operations required before /usr is mounted


Generic Security Service (GSS) Application Program Interface configuration files 


Configuration files for Internet services 


Scripts for changing between run levels 


Dynamic linking libraries needed when /usr is not available


Logical link control (llc2) driver configuration files


Configuration information for the printer subsystem 


Mail subsystem configuration information 


Configuration information for TI (transport- independent) network services 


NFS server logging configuration file 


OpenWindowsTM configuration files


Configuration information for optional packages 


Scripts for entering/leaving run level 0 


Scripts for entering/leaving run level 1 


Scripts for entering/leaving run level 2 


Scripts for entering/leaving run level 3 


Scripts for bringing the system up in single user mode 


This directory may contain a NIS+ authentication configuration file 


Service access facility files (including FIFOs) 


Basic Security Module (BSM) configuration files 


Default profile scripts for new user accounts 


Trademark files; contents displayed at boot time 


uucp configuration information


Default directory for users' home directories, client file systems, or other shared file systems 


Default directory or mount point for a user's home directory on a standalone system. When AutoFS is running, you cannot create any new entries in this directory. 


Directory of platform-independent loadable kernel modules required as part of the boot process. It includes the generic part of the core kernel that is platform independent, /kernel/genunix. See Table 40-3 for the /platform and /usr/platform directory structure.


Convenient, temporary mount point for file systems 


Default directory or mount point for add-on application packages 


Essential executables used in the booting process and in manual system failure recovery 


Standalone programs 


Temporary files; cleared during boot sequence 


Mount point for the /usr file system. See Table 40-2 for more information.


Directory for varying files, which usually includes temporary, logging, or status files 


System logging and accounting files 


Basic Security Module (BSM) audit files 


Default depository for kernel crash dumps 


cron's log file


Solstice Enterprise AgentsTM (SEA) Desktop Management Interface (DMI) run time components


dtlogin configuration files


FTP server directory 


IPv6 router state files 


System log files 


Line printer subsystem logging information  


Directory where users' mail is kept 


Community service messages (note: not the same as USENET-style news)


NIS+ databases 


NFS server log files 


Network Time Protocol (NTP) server state directory 


Root of a subtree for varying files associated with software packages 


Backup files for vi and ex


Temporary system files that are not needed across system reboots. This is a TMPFS-mounted directory. 


Databases maintained by the software package management utilities 


saf (service access facility) logging and accounting files


Directories for spooled temporary files 


cron and at spool files


Spooling lock files 


Line printer spool files 


Mail queued for delivery 


Spooled packages 


Queued uucp jobs


Files deposited by uucp


Network status monitor files 


Directory for temporary files; not cleared during boot sequence 


uucp log and status files


NIS databases (for backwards compatibility with NIS and unnecessary after full transition to NIS+) 

The table below describes the default directories in the /usr file system.

Table 40-2 Default Directories in the /usr File System




SunOS 4.1 binary compatibility package libraries 


Symbolic link to the /usr/bin directory


Symbolic link to the /usr/openwin directory


Symbolic link to the /var/adm directory


Directory for Automated Security Enhancement Tools (ASET) programs and files 


Location for standard system commands 


C compilation programs and libraries 


Demo programs and data 


Symbolic link to the /usr/share/lib/dict directory, which contains the dictionary file used by the UNIX spell program


Directory or mount point for CDE software 


An empty directory, which is a remnant of the SunOS 4.0/4.1 software 


Header files (for C programs, etc.) 


Directories containing JavaTM programs and libraries


Additional kernel modules 


Implementation architecture-specific binaries and libraries 


Various program libraries, architecture-dependent databases, and binaries not invoked directly by the user 


Commands local to a site 


Symbolic link to the /var/mail directory


Symbolic link to the /usr/share/man directory


Directory for network listener services 


Symbolic link to the /var/news directory


Files pertaining to the Form and Menu Language Interpreter (FMLI) execution environment 


Programs that are being phased out 


Directory or mount point for OpenWindows software 


Perl 5 programs and documentation 


See Table 40-3 for more information


Symbolic link to the /var/preserve directory


Directory for the proc tools


Files for online man page and character processing 


Various files and directories related to system administration 


Executables for system administration 


Statically linked version of selected programs from /usr/bin and /usr/sbin


Architecture-independent sharable files 


Architecture-independent databases 


Source code for kernel, libraries, and utilities 


Programs and libraries related to system and network administration  


Symbolic link to the /var/spool directory


Symbolic link to the share/src directory


Symbolic link to the var/tmp directory


Berkeley compatibility package binaries 


Berkeley compatibility package header files 


Berkeley compatibility package libraries 


Directory for Framed Access Command Environment (FACE) programs 


Directory for POSIX-compliant utilities