May 22, 2008 HIER 7

### NAME

hier - layout of filesystems

### DESCRIPTION

An outline of the filesystem hierarchy.

Naming is very important. The UNIX System relies on filename conventions for much of its power as a system. The following file system layout describes generally where things are and what they are, with references to other man pages for more detailed documentation.

Not all files will be in every system.

/
  root directory of the system

/COPYRIGHT
  system copyright notice, most often put on CD-ROM distributions.

/[a-z]/
  user filesystems

/altroot/
  alternate root filesystem, in case of disaster

/bin/
  utilities used in both single and multi-user environments

/boot*
  second-stage boot loader(s) for some platforms; see installboot(8)

/dev/
  block, character and other special device files

  MAKEDEV
    script for creating device files; see makedev(8)
  console
    the computer's console device
  drum
    system swap space; see drum(4)
  fd/
    file descriptor files; see fd(4)
  klog
    kernel logging device; see syslog(3)
  kmem
    kernel virtual memory device; see mem(4)
  log
    UNIX domain datagram log socket; see syslogd(8)
  mem
    kernel physical memory device; see mem(4)
  null
    the null device; see null(4)
  stderr
  stdin
  stdout
    file descriptor files; see fd(4)
  tty
    process' controlling terminal device; see tty(4)
  zero
    the zero device; see zero(4)

/etc/
  system configuration files and scripts

  amd*
    configuration files for amd(8)
  changelist
    files backed up by the security script
  crontab
    schedule used by the cron(8) daemon
  csh.cshrc
  csh.login
  csh.logout
    system-wide scripts for csh(1)
  daily
    script run each day by cron(8)
  daily.conf
    configuration file for daily; see daily.conf(5)
  defaults/
    default configuration files read by various ```/etc/*.conf` files
  disktab
    disk description file, see disktab(5)
  dm.conf
    dungeon master configuration; see dm.conf(5)
  dumpdates
    dump history; see dump(8)
  exports
    filesystem export information; see mountd(8)
  fstab
    filesystem information; see fstab(5) and mount(8)
  ftpusers
    users denied ftp(1) access; see ftpd(8)
  ftpwelcome
    ftp(1) initial message; see ftpd(8)
  gettytab
    terminal configuration database; see gettytab(5)
  group
    group permissions file; see group(5)
  hosts
    host name database backup for named(8); see hosts(5)
  hosts.equiv
    trusted machines with equivalent user ID's
  hosts.lpd
    trusted machines with printing privileges
  inetd.conf
    Internet server configuration file; see inetd(8)
  kerberosV/
    configuration files for the kerberos version V; see kerberos(8)
  localtime
    local timezone information; see ctime(3)
  mail/
    configuration files for sendmail(8)

    aliases*
      name alias files
    sendmail.*
      sendmail(8) configuration information
  mail.rc
    system-wide initialization script for mail(1)
  man.conf
    configuration file for man(1); see man.conf(5)
  master.passwd
    Main password file, readable only by root; see passwd(5)
  mk.conf
    optional file containing make(1) variables, read by pkgsrc and the system sources.
  monthly
    script run each month by cron(8)
  monthly.conf
    configuration file for monthly; see monthly.conf(5)
  motd
    system message of the day
  mtree/
    mtree configuration files; see mtree(8)
  named.*
  namedb/
    named configuration files and databases; see named(8)
  netgroup
    network groups; see netgroup(5)
  netstart
    network startup script
  networks
    network name data base; see networks(5)
  passwd
    World readable password file generated from master.passwd; see passwd(5), pwd_mkdb(8)
  phones
    remote host phone number data base; see phones(5)
  printcap
    system printer configuration; see printcap(5)
  protocols
    protocol name database; see protocols(5)
  pwd.db
    database form of passwd file; see pwd_mkdb(8)
  rc
    master system startup script invoked by init(8); see rc(8)
  rc.conf
    configuration file for system startup and shutdown scripts; see rc.conf(5)
  rc.d/
    directory containing per-subsystem startup and shutdown scripts; see rc(8)
  rc.local
    locally editable system startup script
  rc.shutdown
    master system shutdown script invoked by shutdown(8); see rc(8)
  remote
    remote host description file; see remote(5)
  security
    daily (in)security script run by cron(8)
  security.conf
    configuration file for security; see security.conf(5)
  services
    service name data base; see services(5)
  shells
    list of permitted shells; see shells(5)
  sliphome/
    SLIP login/logout scripts; see sliplogin(8)
  spwd.db
    database form of master.passwd file; see pwd_mkdb(8)
  syslog.conf
    syslogd(8) configuration file; see syslog.conf(5)
  termcap
    terminal type database; see termcap(3)
  ttys
    terminal initialization information; see ttys(5)
  uucp/
    UUCP configuration files; see uucp(1) and uucico(8).
  weekly
    script run each week by cron(8)
  weekly.conf
    configuration file for weekly; see weekly.conf(5)

/home/
  mount point for the automounter; see amd(8)

/lib/
  dynamic linked libraries used by dynamic linked programs (such as those in ```/bin/` and ```/sbin/`) that cannot rely upon ```/usr/lib/` being available.

/libexec/
  system utilities (such as the dynamic linker) required by programs and libraries that cannot rely upon ```/usr/libexec/` being available.

/mnt/
  empty directory commonly used by system administrators as a temporary mount point

/netbsd
  pure kernel executable (the operating system loaded into memory at boot time).

/rescue/
  statically linked rescue tools, for use in system recovery

/root/
  home directory for the super-user

  .cshrc
    super-user start-up file
  .login
    super-user start-up file
  .profile
    super-user start-up file
  .rhosts
    super-user id mapping between machines

/sbin/
  system programs and administration utilities used in both single-user and multi-user environments

/stand/
  programs used in a standalone environment

/tmp/
  temporary files, usually a mfs(8) memory-based filesystem (the contents of ```/tmp` are usually not preserved across a system reboot)

/usr/
  contains the majority of the system utilities and files

  X11R6/
    X11 files

    bin/
      X11 binaries
    include/
      X11 include files
    lib/
      X11 libraries

  bin/
    common utilities, programming tools, and applications
  games/
    the important stuff
  include/
    standard C include files

    arpa/
      include files for Internet service protocols
    atf/
      include files for the Automated Testing Framework; see atf(1)
    g++/
      include files for the C++ compiler
    machine/
      machine specific include files
    net/
    netatalk/
      C include files for AppleTalk protocols miscellaneous network include files; see atalk(4)
    netinet/
      include files for Internet standard protocols; see inet(4)
    netinet6/
      include files for Internet protocol version 6; see inet6(4)
    netiso/
      include files for ISO standard protocols; see iso(4)
    netkey/
      include files for secret key management, used for security protocols; see ipsec(4)
    netnatm/
      C include files for native mode ATM
    nfs/
      C include files for NFS (Network File System)
    protocols/
      C include files for Berkeley service protocols
    sys/
      system C include files (kernel data structures)
    ufs/
      C include files for UFS (The U-word File System)

  lib/
    archive, profiled, position independent archive, and shared libraries
  libdata/
    miscellaneous utility data files
  libexec/
    system daemons & system utilities (executed by other programs)

    uucp/
      UUCP binaries and scripts (historically placed; to be moved)

  lkm/
    loadable kernel modules
  mdec/
    boot blocks, etc.
  obj/
    architecture-specific target tree produced by building the ```/usr/src` tree; normally a symbolic link or mounted filesystem
  pkg/
    packages maintained by groups other than the NetBSD Project.

    bin/
      contributed binaries
    include/
      contributed include files
    lib/
      contributed libraries
    libdata/
      contributed data files
    libexec/
      contributed daemons
    sbin/
      contributed system utilities

  pkgsrc/
    build descriptions ("packages") for the NetBSD packages system.

    distfiles/
      Where unchanged source archives are fetched to/stored
    packages/
      Where compiled binary packages are stored

    There are also several other subdirectories which contain packages of a certain category, e.g., archivers, graphics, ...

  sbin/
    system daemons and system utilities (normally executed by the super-user)
  share/
    architecture-independent text files

    calendar/
      a variety of calendar files; see calendar(1)
    dict/
      word lists; see look(1) and spell(1)

      words
        common words
      web2
        words of Webster's 2nd International
      papers/
        reference databases; see refer(1)
      special/
        custom word lists; see spell(1)

    doc/
      miscellaneous documentation; source for most of the printed 4.3BSD manuals (available from the USENIX association)
    games/
      text files used by various games
    i18n/
      internationalization databases; see iconv(3)
    lkm/
      documentation on the loadable kernel modules interface
    locale/
      locale databases and gettext message catalogs; see setlocale(3) and gettext(3)
    man/
      formatted manual pages
    me/
      macros for use with the me(7) macro package
    misc/
      miscellaneous system-wide text files

      termcap
        terminal characteristics database; see termcap(5)

    mk/
      include files for make(1)
    ms/
      macros for use with the ms(7) macro package
    nls/
      message catalogs; see catgets(3)
    skel/
      sample initialization files for new user accounts
    tabset/
      tab description files for a variety of terminals, used in the termcap file; see termcap(5)
    tmac/
      text processing macros; see nroff(1) and troff(1)
    zoneinfo/
      timezone configuration information; see tzfile(5)
  tests/
    test programs; see atf-run(1) for information on how to run them

/usr/src/
  NetBSD and local source files

  bin/
    source for utilities/files in ```/bin`
  common/
    sources shared between kernel and userland
  crypto/
    cryptographic source, which may have import or export restrictions
  dist/
    third-party `virgin' source code, referenced by other parts of the source tree
  distrib/
    tools and data-files for making distributions
  doc/
    documentation about the source tree (i.e., about the tree, not about how to use the built software.)
  etc/
    source (usually example files) for files in ```/etc`
  external/
    source for programs from external third parties (where NetBSD is the not the primary maintainer), grouped by license, and then products per license

    bsd/
      BSD (or equivalent) licensed software, possibly with the ``advertising clause''

  games/
    source for utilities/files in ```/usr/games`
  gnu/
    source for programs covered by the GNU license (or similar)
  include/
    source for files in ```/usr/include`
  lib/
    source for libraries in ```/usr/lib`
  libexec/
    source for utilities/files in ```/usr/libexec`
  regress/
    various regression tests
  rescue/
    source/makefiles for /rescue
  sbin/
    source for utilities/files in ```/sbin`
  share/
    source for files in ```/usr/share`

    doc/

      papers/
        source for various Berkeley technical papers
      psd/
        source for Programmer's Supplementary Documents
      smm/
        source for System Manager's Manual
      usd/
        source for User's Supplementary Documents

  sys/
    kernel source files

    arch/
      architecture-specific support

      acorn26/
        Acorn Archimedes, A-series and R-series systems
      acorn32/
        Acorn RiscPC/A7000 and VLSI RC7500
      algor/
        Algorithmics Ltd. MIPS evaluations boards
      alpha/
        Digital/Compaq Alpha
      amd64/
        Computers with x86_64 capable CPUs
      amiga/
        Commodore Amiga and MacroSystem DraCo
      amigappc/
        PowerPC based Amiga boards
      arc/
        MIPS-based machines following the Advanced RISC Computing spec
      arm/
        ARM processor general support
      atari/
        Atari TT030, Falcon and Hades
      bebox/
        Be Inc. BeBox
      cats/
        Chalice Technology's CATS and Intel's EBSA-285 evaluation boards
      cesfic/
        CES FIC8234 VME processor board
      cobalt/
        Cobalt Networks' MIPS-based Microserver
      dreamcast/
        Sega Dreamcast game console
      evbarm/
        ARM based evaluation boards
      evbmips/
        MIPS based evaluation boards
      evbppc/
        PowerPC based evaluation boards and appliances
      evbsh3/
        SH3/SH4 based evaluation boards
      ews4800mips/
        NEC's MIPS based EWS4800 workstations
      hp300/
        Hewlett-Packard 9000/300 and 400 680x0-based workstations
      hp700/
        Hewlett-Packard 9000/700 HPPA based workstations
      hpcarm/
        StrongARM based WinCE PDA machines
      hpcmips/
        MIPS based WinCE PDA machines
      hpcsh/
        Hitachi SH3/4 based WinCE PDA machines
      hppa/
        HPPA processor general support
      i386/
        80x86-based IBM PCs and clones
      ibmnws/
        IBM Network Station 1000
      iyonix/
        Castle Technology's Iyonix ARM based PCs
      luna68k/
        Omron Tateishi Electric's 680x0-based LUNA workstations
      m68k/
        680x0 processor general support
      mac68k/
        Apple Macintosh with 68k CPU
      macppc/
        Apple Power Macintosh and clones
      mips/
        MIPS processor general support
      mipsco/
        MIPS Computer Systems Inc. family of workstations and servers
      mmeye/
        Brains Inc. SH3 based mmEye multimedia server
      mvme68k/
        Motorola MVME 680x0-based SBCs
      mvmeppc/
        Motorola PowerPC VME SBCs
      netwinder/
        StrongARM based NetWinder machines
      news68k/
        Sony's 680x0-based NEWS workstations
      newsmips/
        Sony's MIPS-based NEWS workstations
      next68k/
        NeXT 68k "black" hardware
      ofppc/
        Open Firmware PowerPC workstations
      playstation2/
        SONY PlayStation 2
      pmax/
        Digital MIPS-based DECstations and DECsystems
      powerpc/
        PowerPC processor support
      prep/
        PReP (PowerPC Reference Platform) and CHRP machines
      sandpoint/
        Motorola Sandpoint reference platform
      sbmips/
        Broadcom/SiByte evaluation boards
      sgimips/
        Silicon Graphics' MIPS-based workstations
      sh3/
        SH3/SH4 processor general support
      shark/
        Digital DNARD ("Shark")
      sparc/
        Sun Microsystems SPARC (32-bit) and UltraSPARC (in 32-bit mode)
      sparc64/
        Sun Microsystems UltraSPARC (in native 64-bit mode)
      sun2/
        Sun Microsystems 68010-based Sun 2 architecture
      sun3/
        Sun Microsystems 68020/68030-based Sun 3/3x architecture
      sun68k/
        680x0-based Sun architecture general support
      vax/
        Digital VAX
      x68k/
        Sharp X680x0 680x0-based workstations
      x86/
        General support for PC/AT compatibles with ia32 or x86_64 CPUs
      xen/
        The Xen virtual machine monitor
      zaurus/
        Sharp C3x00 Arm based PDA

    compat/
      kernel compatibility modules directory

      common/
        common compatibility routines, old 4BSD and NetBSD routines.
      freebsd/
        support for FreeBSD binaries; see compat_freebsd(8)
      hpux/
        support for 68000 HP-UX binaries
      ibcs2/
        support for Intel Binary binaries
      linux/
        support for Linux binaries; see compat_linux(8)
      m68k4k/
        support for 4KB page 68000 binaries
      netbsd32/
        support for NetBSD 32-bit binaries on 64 bit platforms with compatible CPU families
      osf1/
        support for Digital UNIX (formerly OSF/1) binaries
      ossaudio/
        support for OSS audio
      pecoff/
        support for Win32 binaries; see compat_pecoff(8)
      sunos/
        support for SunOS 4.x binaries; see compat_sunos(8)
      svr4/
        support for System V Release 4 binaries; see compat_svr4(8)
      ultrix/
        support for ULTRIX binaries
      vax1k/
        support for older VAX binaries that started on a 1 KB boundary

    conf/
      architecture independent configuration directory
    crypto/
      cryptographic kernel source, which may have import or export restrictions
    ddb/
      in kernel debugger
    dev/
      architecture independent device support
    fs/
      miscellaneous file systems
      adosfs/
        AmigaDOS file-system support; see mount_ados(8)
      cd9660/
        support for the ISO-9660 filesystem; see mount_cd9660(8)
      filecorefs/
        support for the Acorn RISC OS filecore filesystem; see mount_filecore(8)
      msdosfs/
        MS-DOS file system; see mount_msdos(8)
      ntfs/
        NTFS filesystem support; see mount_ntfs(8)
      ptyfs/
        pseudo-terminal device filesystem; see mount_ptyfs(8)
      smbfs/
        SMB/CIFS filesystem support; see mount_smbfs(8)
      union/
        union file system; see mount_union(8)
    gdbscripts/
      support for accessing kernel structures from within the debugger gdb(1).
    ipkdb/
      support for kernel debugging over the network

    kern/
      support for the high kernel (system calls)
    lib/
      kernel libraries

      libkern/
        C library routines used in the kernel
      libsa/
        machine independent stand alone kernel library
      libz/
        compression library

    lkm/
      loadable kernel modules

      compat/
        LKM support compatibility modules; currently unsupported.
      netinet/
        LKM support networking modules

        if_ipl/
          LKM for IP-Filter

      vfs/
        LKM support for file systems.

    miscfs/
      miscellaneous file systems

      deadfs/
        kernel only dead file system
      fdesc/
        file descriptor file system; see mount_fdesc(8)
      fifofs/
        POSIX FIFO support
      genfs/
        kernel only generic file system
      kernfs/
        kernel namespace file system; see mount_kernfs(8)
      nullfs/
        loop back file system; see mount_null(8)
      overlay/
        overlay file system; see mount_overlay(8)
      portal/
        portal file system; see mount_portal(8)
      procfs/
        process file system; see mount_procfs(8)
      specfs/
        kernel only special file system
      syncfs/
        kernel trickle sync algorithm
      umapfs/
        user and group re-mapping file system; see mount_umap(8)

    net/
      miscellaneous networking support
    netatalk/
      AppleTalk networking support
    netinet/
      IP networking support
    netinet6/
      IPv6 networking support
    netiso/
      ISO networking support
    netkey/
      Key database for IPsec networking support
    netnatm/
      ATM networking support
    nfs/
      NFS support
    stand/
      kernel standalone support
    sys/
      kernel (and system) include files
    ufs/
      local filesystem support

      ffs/
        the Berkeley Fast File System
      lfs/
        the log-structured file system
      mfs/
        the in-memory file system
      ufs/
        shared UNIX file system support
    uvm/
      UVM virtual memory system
  tests/
    source for test programs in ```/usr/tests`
  usr.bin/
    source for utilities/files in ```/usr/bin`
  usr.sbin/
    source for utilities/files in ```/usr/sbin`

/var/
  multi-purpose log, temporary, transient, and spool files

  account/
    system accounting files

    acct
      execution accounting file; see acct(5)

  at/
    timed command scheduling files; see at(1)
  backups/
    miscellaneous backup files, largely of files found in ```/etc`
  chroot/
    home directories of applications which are run in a chroot(8) ``cage''.
  crash/
    system crash dumps; see savecore(8)
  cron/
    scheduled commands configuration files; see cron(8)
  db/
    miscellaneous automatically generated system-specific database files, and persistent files used in the maintenance of third party software.

    pkg
      default location for metadata related to third party software packages. See pkg_install(1) for more details of the NetBSD Packages Collection, or pkgsrc.

  games/
    miscellaneous game status and log files
  heimdal/
    Kerberos 5 KDC database; see kdc(8)
  log/
    miscellaneous system log files

    amd.*
      amd(8) logs
    daily.out
      output of the last run of the ```/etc/daily` script
    ftp.*
      ftp(1) logs
    kerberos.*
      kerberos(8) logs
    lastlog
      system last time logged in log; see utmp(5)
    lpd-errs.*
      printer daemon error logs; see lpd(8)
    maillog.*
      sendmail(8) log files
    messages.*
      general system information log
    monthly.out
      output of the last run of the ```/etc/monthly` script
    secure
      sensitive security information log
    sendmail.st
      sendmail(8) statistics
    timed.*
      timed(8) logs
    weekly.out
      output of the last run of the ```/etc/weekly` script
    wtmp
      login/logout log; see utmp(5)

  mail/
    user system mailboxes
  msgs/
    system messages; see msgs(1)
  preserve/
    temporary home of files preserved after an accidental death of ex(1) or vi(1)
  quotas/
    filesystem quota information
  run/
    system information files, rebuilt after each reboot

    utmp
      database of current users; see utmp(5)

  rwho/
    rwho data files; see rwhod(8), rwho(1), and ruptime(1)
  spool/
    miscellaneous printer and mail system spooling directories

    ftp/
      commonly ``~ftp'', the anonymous ftp root directory; see ftpd(8)
    mqueue/
      sendmail mail queue; see sendmail(8)
    news/
      Network news archival and spooling directories
    output/
      printer spooling directories
    postfix/
      postfix mail queue; see postfix(1)
    uucp/
      uucp spool directory
    uucppublic/
      commonly ``~uucp'', the uucp public temporary directory; see uucp(1)

  tmp/
    temporary files that are not discarded between system reboots

    vi.recover/
      recovery directory for new vi(1)

  yp/
    Databases and configuration for the NIS (YP) system; see nis(8).

### SEE ALSO

apropos(1), ls(1), whatis(1), whereis(1), which(1)

### HISTORY

A hier manual page appeared in Version 7 `AT&T UNIX`.