nfsref(8) — Linux manual page

NAME | SYNOPSIS | INTRODUCTION | DESCRIPTION | EXAMPLES | FILES | SEE ALSO | AUTHOR | COLOPHON


NFSREF(8)                System Manager's Manual               NFSREF(8)

NAME         top

       nfsref - manage NFS referrals

SYNOPSIS         top

       nfsref [-?d] [-t type] add pathname server export [ server export
       ... ]

       nfsref [-?d] [-t type] remove pathname

       nfsref [-?d] [-t type] lookup pathname

INTRODUCTION         top

       NFS version 4 introduces the concept of file system referrals to
       NFS.  A file system referral is like a symbolic link on a file
       server to another file system share, possibly on another file
       server.  On an NFS client, a referral behaves like an automounted
       directory.  The client, under the server's direction, mounts a
       new NFS export automatically when an application first accesses
       that directory.

       Referrals are typically used to construct a single file name
       space across multiple file servers.  Because file servers control
       the shape of the name space, no client configuration is required,
       and all clients see the same referral information.

       The Linux NFS server supports NFS version 4 referrals.
       Administrators can specify the refer= export option in
       /etc/exports to configure a list of exports from which the client
       can choose.  See exports(5) for details.

DESCRIPTION         top

       The nfsref(8) command is a simple way to get started managing
       junction metadata.  Other administrative commands provide richer
       access to junction information.

   Subcommands
       Valid nfsref(8) subcommands are:

       add    Adds junction information to the directory named by
              pathname.  The named directory must already exist, and
              must not already contain junction information.  Regular
              directory contents are obscured to NFS clients by this
              operation.

              A list of one or more file server and export path pairs is
              also specified on the command line.  When creating an NFS
              basic junction, this list is stored in an extended
              attribute of the directory.

              If junction creation is successful, the nfsref(8) command
              flushes the kernel's export cache to remove previously
              cached junction information.

       remove Removes junction information from the directory named by
              pathname.  The named directory must exist, and must
              contain junction information.  Regular directory contents
              are made visible to NFS clients again by this operation.

              If junction deletion is successful, the nfsref(8) command
              flushes the kernel's export cache to remove previously
              cached junction information.

       lookup Displays junction information stored in the directory
              named by pathname.  The named directory must exist, and
              must contain junction information.

              When looking up an NFS basic junction, the junction
              information in the directory is listed on stdout.

   Command line options
       -d, --debug
              Enables debugging messages during operation.

       -t, --type=junction-type
              Specifies the junction type for the operation.  Valid
              values for junction-type are nfs-basic or nfs-fedfs.

              For the add subcommand, the default value if this option
              is not specified is nfs-basic.  For the remove and lookup
              subcommands, the --type option is not required.  The
              nfsref(8) command operates on whatever junction contents
              are available.

EXAMPLES         top

       Suppose you have two file servers, top.example.net and
       home.example.net.  You want all your clients to mount
       top.example.net:/ and then see the files under home.example.net:/
       automatically in top:/home.

       On top.example.net, you might issue this command as root:

              # mkdir /home
              # nfsref --type=nfs-basic add /home home.example.net /
              Created junction /home.

FILES         top

       /etc/exports
              NFS server export table

SEE ALSO         top

       exports(5)

       RFC 5661 for a description of NFS version 4 referrals

AUTHOR         top

       Chuck Lever <chuck.lever@oracle.com>

COLOPHON         top

       This page is part of the nfs-utils (NFS utilities) project.
       Information about the project can be found at 
       ⟨http://linux-nfs.org/wiki/index.php/Main_Page⟩.  If you have a
       bug report for this manual page, see
       ⟨http://linux-nfs.org/wiki/index.php/Main_Page⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨http://git.linux-nfs.org/?p=steved/nfs-utils.git;a=summary⟩ on
       2021-08-27.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-21.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

                               9 Jan 2018                      NFSREF(8)

Pages that refer to this page: nfsref(8)