MNTENT(5)           UNIX Programmer's Manual            MNTENT(5)

NAME
     mntent, fstab - static information about filesystems

SYNOPSIS
     #include <mntent.h>

DESCRIPTION
     NOTE:  Unless NetInfo is disabled, /etc/fstab is accessed
     only at boot time, when it's used to mount all file systems
     of type 4.3.

     The file /etc/fstab describes the file systems and swapping
     partitions used by the local machine.  It is created by the
     system administrator using a text editor, and processed by
     commands which mount, unmount, check consistency of, dump
     and restore file systems, and by the system in providing
     swap space.

     It consists of a number of lines of the form:

          fsname dir type opts freq passno

     an example of which would be:

          /dev/xy0a / 4.3 rw,noquota 1 2

     The entries in this file are accessed using the routines in
     getmntent(3), which returns a structure of the following
     form:

          struct mntent {
                 char  *mnt_fsname;  /* file system name */
                 char  *mnt_dir;     /* file system path prefix */
                 char  *mnt_type;    /* 4.3, nfs, dos, macintosh, nucfs, cfs, or ignore */
                 char  *mnt_opts;    /* ro, etc. */
                 int   mnt_freq;     /* dump frequency, in days */
                 int   mnt_passno;   /* pass number on parallel fsck */
          };

     There is one entry per line in the file, and the fields are
     separated by white space.  A ``#'' as the first non-white
     character indicates a comment.

     The mnt_opts field consists of a string of comma separated
     options.  Some of the options are common to all filesystem
     types, and others only make sense for a single filesystem
     type.  It is important to specify that a removable filesys-
     tem (such as floppy disk) is removable, or ro if a filesys-
     tem is read-only.  See mount(8) for a more complete descrip-
     tion of the options available.

     The mnt_type field determines how the mnt_fsname, and
     mnt_opts fields will be interpreted.  Below is a list of the
     file system types currently supported and the way each of
     them interprets these fields.  See
     /NextDeveloper/Headers/bsd/mntent.h for additional, though
     unsupported, file system types.

     4.3

          mnt_fsname  Must be a block special device.

          mnt_opts    Valid opts are: ro, rw, suid, nosuid.

     nfs

          mnt_fsname  servername:volumename to be mounted

          mnt_opts    Valid opts are: ro, rw, nosuid, hard, soft,
                      bg, fg, retry, rsize, wsize, timeo,
                      retrans, port, intr, net, secure, grpid,
                      nosub, multi, acregmin, acregmax, noac,
                      acdirmin, acdirmax.

     dos

          mnt_fsname  Must be a raw device.

          mnt_opts    Ignored.

          NOTE:  This file system does not support SCSI hard
          disks, CD-ROMs, or 2.88 MB floppies; it supports only
          720KB and 1.4 MB floppies.  To mount a dos volume, the
          appropriate loadable kernel server must already be
          loaded into the system.

     macintosh

          mnt_fsname  Must be a raw device.

          mnt_opts    Ignored.

          NOTE:  To mount a macintosh volume, the appropriate
          loadable kernel server must already be loaded into the
          system.

     nucfs (NetWare UNIX Client file system)

          mnt_fsname  servername:volumename to be mounted

          mnt_opts    Valid opts are:  ro, uid=someuser.

          NOTE:  To mount a nucfs volume you must be root. In
          addition, either root must be authenticated to the
          NetWare server, or the mount option uid=someuser must
          be included to specify the UNIX user name or uid of a
          NeXT user who is already authenticated to the NetWare
          server.

     cfs (CD-ROM file system)

          mnt_fsname  Must be a raw device.

          mnt_opts    Ignored.

          NOTE:  To mount a cfs volume, the appropriate loadable
          kernel server must already be loaded into the system.

     If the mnt_type is specified as ``ignore'' the entry is
     ignored.  This is useful to show disk partitions which are
     currently not used.  Disks that are specified as as
     ``ignore'' are also not automounted by the Workspace in
     NEXTSTEP.  This is useful when your disk has data in a for-
     mat that NEXTSTEP doesn't recognize, and you want it to
     ignore the disk.

     The field mnt_freq indicates how often each partition should
     be dumped by the dump(8) command (and triggers that
     command's w option which tells which file systems should be
     dumped).  Most systems set the mnt_freq field to 1, indicat-
     ing that the file systems are dumped each day.

     The final field mnt_passno is used by the disk consistency
     check program fsck(8) to allow overlapped checking of file
     systems during a reboot.  All file systems with mnt_passno
     of 1 are first checked simultaneously, then all file systems
     with mnt_passno of 2, and so on.  It is usual to make the
     mnt_passno of the root file system have the value 1, and
     then check one file system on each available disk drive in
     each subsequent pass to the exhaustion of file system parti-
     tions.

     /etc/fstab is only read by programs, and not written; it is
     the duty of the system administrator to properly create and
     maintain this file.  The order of records in /etc/fstab is
     important because fsck, mount, and umount process the file
     sequentially; file systems must appear after file systems
     they are mounted within.

FILES
     /etc/fstab

SEE ALSO
     fsck(8), getmntent(3), mount(8), quotacheck(8), quotaon(8),
     umount(8)