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filesystem(5)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO

NAME

filesystem- file system organization

SYNOPSIS

/usr

/export

DESCRIPTION

The file system tree is organized for administrative convenience. Distinct areas within the file system tree are provided for files that are private to one machine, files that can be shared by multiple machines of a common architecture, files that can be shared by all machines, and home directories. This organization allows sharable files to be stored on one machine but accessed by many machines using a remote file access mechanism such as NFS. Grouping together similar files makes the file system tree easier to upgrade and manage.

The file system tree consists of a root file system and a collection of mountable file systems. The mount(2) program attaches mountable file systems to the file system tree at mount points (directory entries) in the root file system or other previously mounted file systems. Two file systems, / (the root) and /usr, must be mounted in order to have a completely functional system. The root file system is mounted automatically by the kernel at boot time; the /usr file system is mounted by the system start-up script, which is run as part of the booting process.

Root File System

The root file system contains files that are unique to each machine. It contains the following directories:

/dev: Primary location for special files. Typically, device files are built to match the kernel and hardware configuration of the machine.
/dev/dsk: Block disk devices.
/dev/pts: Pseudo-terminal devices.
/dev/rdsk: Raw disk devices.
/dev/rmt: Raw tape devices.
/dev/sad: Entry points for the STREAMS Administrative driver.
/dev/term: Terminal devices.
/etc: Host-specific administrative configuration files and databases. /etc may be viewed as the directory that defines the machine's identity.
/etc/acct: Accounting system configuration information.
/etc/cron.d: Configuration information for cron(1M).
/etc/default: Defaults information for various programs.
/etc/dfs: Configuration information for exported file systems.
/etc/fs: Binaries organized by file system types for operations required before /usr is mounted.
/etc/inet: Configuration files for Internet services.
/etc/init.d: Shell scripts for transitioning between run levels.
/etc/lib: Shared libraries needed during booting.
/etc/lp: Configuration information for the printer subsystem.
/etc/mail: Mail subsystem configuration.
/etc/net: Configuration information for transport independent network services.
/etc/opt: Configuration information for optional packages.
/etc/rc0.d: Scripts for entering or leaving run level 0. See init(1M).
/etc/rc1.d: Scripts for entering or leaving run level 1. See init(1M).
/etc/rc2.d: Scripts for entering or leaving run level 2. See init(1M).
/etc/rc3.d: Scripts for entering or leaving run level 3. See init(1M).
/etc/saf: Service Access Facility files.
/etc/skel: Default profile scripts for new user accounts. See useradd(1M).
/etc/sm: Status monitor information.
/etc/sm.bak: Backup status monitor information.
/etc/tm: Trademark files; contents displayed at boot time.
/etc/uucp: UUCP configuration information. See uucp(1C).
/export: Default root of the exported file system tree.
/home: Default root of a subtree for user directories.
/kernel: Subtree 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 kernel(1M).
/kernel/drv: 32-bit device drivers.
/kernel/drv/sparcv9: 64-bit SPARC device drivers.
/kernel/genunix: Platform-independent kernel.
/mnt: Default temporary mount point for file systems. This is an empty directory on which file systems may be temporarily mounted.
/opt: Root of a subtree for add-on application packages.
/platform: Subtree of Platform Specific objects which need to reside on the root filesystem. It contains a series of directories, one per supported platform. The semantics of the series of directories is equivalent to / (root).
/platform/platform-name/kernel: Platform-dependent objects with semantics equivalent to /kernel. It includes the file unix, the core kernel that is platform-dependent. See kernel(1M).
/platform/platform-name/kernel/sparcv9/unix: 64-bit platform-dependent kernel.
/platform/platform-name/kernel/unix: 32-bit platform-dependent kernel.
/platform/platform-name/lib: Platform Dependent objects with semantics equivalent to /lib.
/platform/platform-name/sbin: Platform Dependent objects with semantics equivalent to /sbin.
/proc: Root of a subtree for the process file system.
/sbin: Essential executables used in the booting process and in manual system recovery. The full complement of utilities is available only after /usr is mounted.
/tmp: Temporary files; cleared during the boot operation.
/var: Root of a subtree for varying files. Varying files are files that are unique to a machine but that can grow to an arbitrary (that is, variable) size. An example is a log file.
/var/adm: System logging and accounting files.
/var/cron: Log files for cron(1M).
/var/mail: Directory where users' mail is kept.
/var/news: Community service messages. This is not the same as USENET-style news.
/var/nis: NIS+ databases.
/var/opt: Root of a subtree for varying files associated with optional software packages.
/var/preserve: Backup files for vi(1) and ex(1).
/var/sadm: Databases maintained by the software package management utilities.
/var/saf: Service access facility logging and accounting files.
/var/spool: Root directory for files used in printer spooling, mail delivery, cron(1M), at(1), and so forth.
/var/spool/cron: cron(1M) and at(1) spooling files.
/var/spool/locks: Spooling lock files.
/var/spool/lp: Line printer spool files. See lp(1).
/var/spool/mqueue: Mail queued for delivery.
/var/spool/pkg: Spooled packages.
/var/spool/uucp: Queued uucp(1C) jobs.
/var/spool/uucppublic: Files deposited by uucp(1C).
/var/tmp: Transitory files; this directory is not cleared during the boot operation.
/var/uucp: uucp(1C) log and status files.
/var/yp: Databases needed for backwards compatibility with NIS and ypbind(1M); unnecessary after full transition to NIS+.

/usr File System

Because it is desirable to keep the root file system small and not volatile, on disk-based systems larger file systems are often mounted on /home, /opt, /usr, and /var.

The file system mounted on /usr contains architecture-dependent and architecture-independent sharable files. The subtree rooted at /usr/share contains architecture-independent sharable files; the rest of the /usr tree contains architecture-dependent files. By mounting a common remote file system, a group of machines with a common architecture may share a single /usr file system. A single /usr/share file system can be shared by machines of any architecture. A machine acting as a file server may export many different /usr file systems to support several different architectures and operating system releases. Clients usually mount /usr read-only so that they do not accidentally change any shared files.

The /usr file system contains the following subdirectories:

/usr/4lib: a.out libraries for the Binary Compatibility Package. See Binary Compatibility Guide
/usr/bin: Primary location for standard system utilities.
/usr/ccs: C compilation system.
/usr/ccs/bin: C compilation commands and system utilities.
/usr/ccs/lib: Symbolic link to /usr/lib.
/usr/demo: Demo programs and data.
/usr/dt: root of a subtree for CDE Motif.
/usr/dt/bin: Primary location for CDE Motif system utilities.
/usr/dt/include: Header files for CDE Motif.
/usr/dt/lib: Libraries for CDE Motif.
/usr/dt/man: On-line reference manual pages for CDE Motif.
/usr/games: Game binaries and data.
/usr/include: Include headers (for C programs).
/usr/java: Solaris Java Virtual Machine.
/usr/kernel: Subtree of platform-independent loadable kernel modules, not needed in the root filesystem.
/usr/lib: Program libraries, various architecture-dependent databases, and executables not invoked directly by the user (for example, system daemons).
/usr/lib/64: Symbolic link to the most portable 64-bit Solaris interfaces.
/usr/lib/acct: Accounting scripts and binaries. See acct(1M).
/usr/lib/class: Scheduling class-specific directories containing executables for priocntl(1) and dispadmin(1M).
/usr/lib/dict: Database files for spell(1).
/usr/lib/font: troff(1) font description files.
/usr/lib/fs: File system type dependent modules; generally not intended to be invoked directly by the user.
/usr/lib/iconv: Conversion tables for iconv(1).
/usr/lib/libp: Profiled libraries.
/usr/lib/locale: Localization databases.
/usr/lib/lp: Line printer subsystem databases and back-end executables.
/usr/lib/mail: Auxiliary programs for the mail(1) subsystem.
/usr/lib/netsvc: Internet network services.
/usr/lib/nfs: Auxiliary NFS-related programs and daemons.
/usr/lib/pics: Position Independent Code (PIC) archives needed to rebuild the run-time linker.
/usr/lib/refer: Auxiliary programs for refer(1).
/usr/lib/sa: Scripts and commands for the system activity report package. See sar(1).
/usr/lib/saf: Auxiliary programs and daemons related to the service access facility.
/usr/lib/sparcv9: 64-bit SPARC libraries.
/usr/lib/spell: Auxiliary programs and databases for spell(1). This directory is only present when the Binary Compatibility Package is installed.
/usr/lib/uucp: Auxiliary programs and daemons for uucp(1C).
/usr/local: Commands local to a site.
/usr/net/servers: Entry points for foreign name service requests relayed using the network listener. See listen(1M).
/usr/oasys: Commands and files related to the optional Framed Access Command Environment (FACE) package. See face(1).
/usr/old: Programs that are being phased out.
/usr/openwin: Installation or mount point for the OpenWindows software.
/usr/platform: Subtree of platform-specific objects which does not need to reside on the root filesystem. It contains a series of directories, one per supported platform. The semantics of the series of directories is equivalent to /platform, except for subdirectories which don't provide utility under one or the other (for example: /platform/include isn't needed).
/usr/platform/platform-name/include: Platform-dependent headers with semantics equivalent to /usr/include.
/usr/platform/platform-name/kernel: Platform-dependent objects with semantics equivalent to /usr/kernel.
/usr/platform/platform-name/lib: Platform-dependent objects with semantics equivalent to /usr/lib.
/usr/platform/platform-name/sbin: Platform-dependent objects with semantics equivalent to /usr/sbin.
/usr/sadm: System administration files and directories.
/usr/sadm/bin: Binaries for the Form and Menu Language Interpreter (FMLI) scripts. See fmli(1).
/usr/sadm/install: Executables and scripts for package management.
/usr/sbin: Executables for system administration.
/usr/sbin/static: Statically linked version of selected programs from /usr/bin and /usr/sbin. These are used to recover from broken dynamic linking and before all pieces necessary for dynamic linking are present.
/usr/share: Architecture-independent sharable files.
/usr/share/lib: Architecture-independent databases.
/usr/share/lib/keytables: Keyboard layout description tables.
/usr/share/lib/mailx: Help files for mailx(1).
/usr/share/lib/nterm: nroff(1) terminal tables.
/usr/share/lib/pub: Character set data files.
/usr/share/lib/spell: Auxiliary scripts and databases for spell(1).
/usr/share/lib/tabset: Tab setting escape sequences.
/usr/share/lib/terminfo: Terminal description files for terminfo(4).
/usr/share/lib/tmac: Macro packages and related files for text processing tools, for example, nroff(1) and troff(1).
/usr/share/lib/zoneinfo: Time zone information.
/usr/share/man: On-line reference manual pages (if present).
/usr/share/src: Source code for utilities and libraries.
/usr/snadm: SNAG files.
/usr/ucb: Berkeley compatibility package binaries. See Source Compatibility Guide
/usr/ucbinclude: Berkeley compatibility package headers.
/usr/ucblib: Berkeley compatibility package libraries.
/usr/vmsys: Commands and files related to the optional FACE package. See face(1). Berkeley compatibility package libraries.

/export File System

A machine with disks may export root file systems, swap files, and /usr file systems to diskless or partially-disked machines that mount them into the standard file system hierarchy. The standard directory tree for sharing these file systems from a server is:

/export: The default root of the exported file system tree.
/export/exec/architecture-name: The exported /usr file system supporting architecture-name for the current release.
/export/exec/architecture-name.release-name: The exported /usr file system supporting architecture-name for release-name.
/export/exec/share: The exported common /usr/share directory tree.
/export/exec/share.release-name: The exported common /usr/share directory tree for release-name.
/export/root/hostname: The exported root file system for hostname.
/export/swap/hostname: The exported swap file for hostname.
/export/var/hostname: The exported /var directory tree for hostname.