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
       2018-04-30.  (At that time, the date of the most recent commit that
       was found in the repository was 2018-04-20.)  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)