filesystem(5)

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).

/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/∗/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/∗/lib Platform Dependent objects with semantics equivalent to /lib.

/platform/∗/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. Note: 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), etc.

/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/bin/sunview1 SunView executables. This directory is only present when the Binary Compatibility Package is installed.

/usr/ccs C compilation system.

/usr/ccs/bin C compilation commands and system utilities.

/usr/ccs/lib Libraries and auxiliary files.

/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, etc).

/usr/kernel Subtree of Platform Independent loadable kernel modules, not needed in the root filesystem.

/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).

/platform/∗/include Platform Dependent headers with semantics equivalent to /usr/include.

/platform/∗/kernel Platform Dependent objects with semantics equivalent to /usr/kernel.

/platform/∗/lib Platform Dependent objects with semantics equivalent to /usr/lib.

/platform/∗/sbin Platform Dependent objects with semantics equivalent to /usr/sbin.

/usr/lib Program libraries, various architecture-dependent databases, and executables not invoked directly by the user (system daemons, etc).

/usr/lib/acct Accounting scripts and binaries. See acct(1M).

/usr/lib/dict Database files for spell(1).

/usr/lib/class Scheduling class-specific directories containing executables for priocntl(1) and dispadmin(1M).

/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/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/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/man On-line reference manual pages (if present).

/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/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.

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