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man/orig/mount(8)

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mount • man/mount • man/orig/mount • Пример использования mount


MOUNT(8) FreeBSD System Manager's Manual MOUNT(8)

Содержание

[править] NAME

    mount — mount file systems

[править] SYNOPSIS

    mount [-adflpruvw] [-F fstab] [-o options] [-t ufs | external_type]
    mount [-dfpruvw] special | node
    mount [-dfpruvw] [-o options] [-t ufs | external_type] special node

[править] DESCRIPTION

    The mount utility calls the nmount(2) system call to prepare and graft a
    special device or the remote node (rhost:path) on to the file system tree
    at the point node.  If either special or node are not provided, the
    appropriate information is taken from the fstab(5) file.
    The system maintains a list of currently mounted file systems.  If no
    arguments are given to mount, this list is printed.
    The options are as follows:
    -a      All the file systems described in fstab(5) are mounted.  Excep‐
            tions are those marked as “noauto”, those marked as “late”
            (unless the -l option was specified), those excluded by the -t
            flag (see below), or if they are already mounted (except the root
            file system which is always remounted to preserve traditional
            single user mode behavior).
    -d      Causes everything to be done except for the actual system call.
            This option is useful in conjunction with the -v flag to deter‐
            mine what the mount command is trying to do.
    -F fstab
            Specify the fstab file to use.
    -f      Forces the revocation of write access when trying to downgrade a
            file system mount status from read-write to read-only.  Also
            forces the R/W mount of an unclean file system (dangerous; use
            with caution).
    -L      When used in conjunction with the -a option, mount only those
            file systems which are marked as “late”.
    -l      When used in conjunction with the -a option, also mount those
            file systems which are marked as “late”.
    -n      For compatibility with some other implementations, this flag is
            currently a no-op.
    -o      Options are specified with a -o flag followed by a comma sepa‐
            rated string of options.  In case of conflicting options being
            specified, the rightmost option takes effect.  The following
            options are available:
            acls    Enable POSIX.1e Access Control Lists, or ACLs, which can
                    be customized via the setfacl(1) and getfacl(1) commands.
                    This flag is mutually exclusive with nfsv4acls flag.
            async   All I/O to the file system should be done asynchronously.
                    This is a dangerous flag to set, since it does not guar‐
                    antee that the file system structure on the disk will
                    remain consistent.  For this reason, the async flag
                    should be used sparingly, and only when some data recov‐
                    ery mechanism is present.
            automounted
                    This flag indicates that the file system was mounted by
                    automountd(8).  Automounted file systems are automati‐
                    cally unmounted by autounmountd(8).
            current
                    When used with the -u flag, this is the same as specify‐
                    ing the options currently in effect for the mounted file
                    system.
            force   The same as -f; forces the revocation of write access
                    when trying to downgrade a file system mount status from
                    read-write to read-only.  Also forces the R/W mount of an
                    unclean file system (dangerous; use with caution).
            fstab   When used with the -u flag, this is the same as specify‐
                    ing all the options listed in the fstab(5) file for the
                    file system.
            late    This file system should be skipped when mount is run with
                    the -a flag but without the -l flag.
            mountprog=⟨program⟩
                    Force mount to use the specified program to mount the
                    file system, instead of calling nmount(2) directly.  For
                    example:
                    mount -t foofs -o mountprog=/mydir/fooprog /dev/acd0 /mnt
            multilabel
                    Enable multi-label Mandatory Access Control, or MAC, on
                    the specified file system.  If the file system supports
                    multilabel operation, individual labels will be main‐
                    tained for each object in the file system, rather than
                    using a single label for all objects.  An alternative to
                    the -l flag in tunefs(8).  See mac(4) for more informa‐
                    tion, which cause the multilabel mount flag to be set
                    automatically at mount-time.
            nfsv4acls
                    Enable NFSv4 ACLs, which can be customized via the
                    setfacl(1) and getfacl(1) commands.  This flag is mutu‐
                    ally exclusive with acls flag.
            noasync
                    Metadata I/O should be done synchronously, while data I/O
                    should be done asynchronously.  This is the default.
            noatime
                    Do not update the file access time when reading from a
                    file.  This option is useful on file systems where there
                    are large numbers of files and performance is more criti‐
                    cal than updating the file access time (which is rarely
                    ever important).  This option is currently only supported
                    on local file systems.
            noauto  This file system should be skipped when mount is run with
                    the -a flag.
            noclusterr
                    Disable read clustering.
            noclusterw
                    Disable write clustering.
            noexec  Do not allow execution of any binaries on the mounted
                    file system.  This option is useful for a server that has
                    file systems containing binaries for architectures other
                    than its own.  Note: This option was not designed as a
                    security feature and no guarantee is made that it will
                    prevent malicious code execution; for example, it is
                    still possible to execute scripts which reside on a
                    noexec mounted partition.
            nosuid  Do not allow set-user-identifier or set-group-identifier
                    bits to take effect.  Note: this option is worthless if a
                    public available suid or sgid wrapper like suidperl(1) is
                    installed on your system.  It is set automatically when
                    the user does not have super-user privileges.
            nosymfollow
                    Do not follow symlinks on the mounted file system.
            ro      The same as -r; mount the file system read-only (even the
                    super-user may not write it).
            snapshot
                    This option allows a snapshot of the specified file sys‐
                    tem to be taken.  The -u flag is required with this
                    option.  Note that snapshot files must be created in the
                    file system that is being snapshotted.  You may create up
                    to 20 snapshots per file system.  Active snapshots are
                    recorded in the superblock, so they persist across
                    unmount and remount operations and across system reboots.
                    When you are done with a snapshot, it can be removed with
                    the rm(1) command.  Snapshots may be removed in any
                    order, however you may not get back all the space con‐
                    tained in the snapshot as another snapshot may claim some
                    of the blocks that it is releasing.  Note that the schg
                    flag is set on snapshots to ensure that not even the root
                    user can write to them.  The unlink command makes an
                    exception for snapshot files in that it allows them to be
                    removed even though they have the schg flag set, so it is
                    not necessary to clear the schg flag before removing a
                    snapshot file.
                    Once you have taken a snapshot, there are three interest‐
                    ing things that you can do with it:
                    1.   Run fsck(8) on the snapshot file.  Assuming that the
                         file system was clean when it was mounted, you
                         should always get a clean (and unchanging) result
                         from running fsck on the snapshot.  This is essen‐
                         tially what the background fsck process does.
                    2.   Run dump(8) on the snapshot.  You will get a dump
                         that is consistent with the file system as of the
                         timestamp of the snapshot.
                    3.   Mount the snapshot as a frozen image of the file
                         system.  To mount the snapshot /var/snapshot/snap1:
                         mdconfig -a -t vnode -f /var/snapshot/snap1 -u 4
                         mount -r /dev/md4 /mnt
                         You can now cruise around your frozen /var file sys‐
                         tem at /mnt.  Everything will be in the same state
                         that it was at the time the snapshot was taken.  The
                         one exception is that any earlier snapshots will
                         appear as zero length files.  When you are done with
                         the mounted snapshot:
                         umount /mnt
                         mdconfig -d -u 4
            suiddir
                    A directory on the mounted file system will respond to
                    the SUID bit being set, by setting the owner of any new
                    files to be the same as the owner of the directory.  New
                    directories will inherit the bit from their parents.
                    Execute bits are removed from the file, and it will not
                    be given to root.
                    This feature is designed for use on fileservers serving
                    PC users via ftp, SAMBA, or netatalk.  It provides secu‐
                    rity holes for shell users and as such should not be used
                    on shell machines, especially on home directories.  This
                    option requires the SUIDDIR option in the kernel to work.
                    Only UFS file systems support this option.  See chmod(2)
                    for more information.
            sync    All I/O to the file system should be done synchronously.
            update  The same as -u; indicate that the status of an already
                    mounted file system should be changed.
            union   Causes the namespace at the mount point to appear as the
                    union of the mounted file system root and the existing
                    directory.  Lookups will be done in the mounted file sys‐
                    tem first.  If those operations fail due to a non-exis‐
                    tent file the underlying directory is then accessed.  All
                    creates are done in the mounted file system.
            Any additional options specific to a file system type that is not
            one of the internally known types (see the -t option) may be
            passed as a comma separated list; these options are distinguished
            by a leading “-” (dash).  For example, the mount command:
                  mount -t cd9660 -o -e /dev/cd0 /cdrom
            causes mount to execute the equivalent of:
                  /sbin/mount_cd9660 -e /dev/cd0 /cdrom
            Options that take a value are specified using the -option=value
            syntax:
                  mount -t msdosfs -o -u=fred,-g=wheel /dev/da0s1 /mnt
            is equivalent to
                  /sbin/mount_msdosfs -u fred -g wheel /dev/da0s1 /mnt
            Additional options specific to file system types which are not
            internally known (see the description of the -t option below) may
            be described in the manual pages for the associated
            /sbin/mount_XXX utilities.
    -p      Print mount information in fstab(5) format.  Implies also the -v
            option.
    -r      The file system is to be mounted read-only.  Mount the file sys‐
            tem read-only (even the super-user may not write it).  The same
            as the ro argument to the -o option.
    -t ufs | external_type
            The argument following the -t is used to indicate the file system
            type.  The type ufs is the default.  The -t option can be used to
            indicate that the actions should only be taken on file systems of
            the specified type.  More than one type may be specified in a
            comma separated list.  The list of file system types can be pre‐
            fixed with “no” to specify the file system types for which action
            should not be taken.  For example, the mount command:
                  mount -a -t nonfs,nullfs
            mounts all file systems except those of type NFS and NULLFS.
            The default behavior of mount is to pass the -t option directly
            to the nmount(2) system call in the fstype option.
            However, for the following file system types: cd9660, mfs,
            msdosfs, nfs, nullfs, oldnfs, smbfs, udf, and unionfs.  mount
            will not call nmount(2) directly and will instead attempt to exe‐
            cute a program in /sbin/mount_XXX where XXX is replaced by the
            file system type name.  For example, nfs file systems are mounted
            by the program /sbin/mount_nfs.
            Most file systems will be dynamically loaded by the kernel if not
            already present, and if the kernel module is available.
    -u      The -u flag indicates that the status of an already mounted file
            system should be changed.  Any of the options discussed above
            (the -o option) may be changed; also a file system can be changed
            from read-only to read-write or vice versa.  An attempt to change
            from read-write to read-only will fail if any files on the file
            system are currently open for writing unless the -f flag is also
            specified.  The set of options is determined by applying the
            options specified in the argument to -o and finally applying the
            -r or -w option.
    -v      Verbose mode.  If the -v is used alone, show all file systems,
            including those that were mounted with the MNT_IGNORE flag and
            show additional information about each file system (including
            fsid when run by root).
    -w      The file system object is to be read and write.

[править] ENVIRONMENT

    PATH_FSTAB  If the environment variable PATH_FSTAB is set, all operations
                are performed against the specified file.  PATH_FSTAB will
                not be honored if the process environment or memory address
                space is considered “tainted”.  (See issetugid(2) for more
                information.)

[править] FILES

    /etc/fstab  file system table

[править] DIAGNOSTICS

    Various, most of them are self-explanatory.
          XXXXX file system is not available
    The kernel does not support the respective file system type.  Note that
    support for a particular file system might be provided either on a static
    (kernel compile-time), or dynamic basis (loaded as a kernel module by
    kldload(8)).

[править] SEE ALSO


[править] HISTORY

    A mount utility appeared in Version 1 AT&T UNIX.

[править] CAVEATS

    After a successful mount, the permissions on the original mount point
    determine if .. is accessible from the mounted file system.  The minimum
    permissions for the mount point for traversal across the mount point in
    both directions to be possible for all users is 0111 (execute for all).
    Use of the mount is preferred over the use of the file system specific
    mount_XXX commands.  In particular, mountd(8) gets a SIGHUP signal (that
    causes an update of the export list) only when the file system is mounted
    via mount.

[править] BUGS

    It is possible for a corrupted file system to cause a crash.

FreeBSD 10.1 August 20, 2014 FreeBSD 10.1