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diff --git a/utils/nfsref/nfsref.man b/utils/nfsref/nfsref.man new file mode 100644 index 0000000..1261549 --- /dev/null +++ b/utils/nfsref/nfsref.man @@ -0,0 +1,180 @@ +.\"@(#)nfsref.8" +.\" +.\" @file utils/nfsref/nfsref.man +.\" @brief man page for nfsref command +.\" + +.\" +.\" Copyright 2011, 2018 Oracle. All rights reserved. +.\" +.\" This file is part of nfs-utils. +.\" +.\" nfs-utils is free software; you can redistribute it and/or modify +.\" it under the terms of the GNU General Public License version 2.0 as +.\" published by the Free Software Foundation. +.\" +.\" nfs-utils is distributed in the hope that it will be useful, but +.\" WITHOUT ANY WARRANTY; without even the implied warranty of +.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +.\" GNU General Public License version 2.0 for more details. +.\" +.\" You should have received a copy of the GNU General Public License +.\" version 2.0 along with nfs-utils. If not, see: +.\" +.\" http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt +.\" +.TH NFSREF 8 "9 Jan 2018" +.SH NAME +nfsref \- manage NFS referrals +.SH SYNOPSIS +.B nfsref +.RB [ \-?d ] +.RB [ \-t +.IB type ] +.B add +.I pathname server export +.RI [ " server" +.IR export " ... ]" +.P +.B nfsref +.RB [ \-?d ] +.RB [ \-t +.IB type ] +.B remove +.I pathname +.P +.B nfsref +.RB [ \-?d ] +.RB [ \-t +.IB type ] +.B lookup +.I pathname +.SH INTRODUCTION +NFS version 4 introduces the concept of +.I 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. +.P +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. +.P +The Linux NFS server supports NFS version 4 referrals. +Administrators can specify the +.B refer= +export option in +.I /etc/exports +to configure a list of exports from which the client can choose. +See +.BR exports (5) +for details. +.P +.SH DESCRIPTION +The +.BR nfsref (8) +command is a simple way to get started managing junction metadata. +Other administrative commands provide richer access to junction information. +.SS Subcommands +Valid +.BR nfsref (8) +subcommands are: +.IP "\fBadd\fP" +Adds junction information to the directory named by +.IR 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. +.IP +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. +.IP +If junction creation is successful, the +.BR nfsref (8) +command flushes the kernel's export cache +to remove previously cached junction information. +.IP "\fBremove\fP" +Removes junction information from the directory named by +.IR pathname . +The named directory must exist, +and must contain junction information. +Regular directory contents are made visible to NFS clients again by this operation. +.IP +If junction deletion is successful, the +.BR nfsref (8) +command flushes the kernel's export cache +to remove previously cached junction information. +.IP "\fBlookup\fP" +Displays junction information stored in the directory named by +.IR pathname . +The named directory must exist, +and must contain junction information. +.IP +When looking up an NFS basic junction, the junction information +in the directory is listed on +.IR stdout . +.SS Command line options +.IP "\fB\-d, \-\-debug" +Enables debugging messages during operation. +.IP "\fB\-t, \-\-type=\fIjunction-type\fP" +Specifies the junction type for the operation. Valid values for +.I junction-type +are +.B nfs-basic +or +.BR nfs-fedfs . +.IP +For the +.B add +subcommand, the default value if this option is not specified is +.BR nfs-basic . +For the +.B remove +and +.B lookup +subcommands, the +.B \-\-type +option is not required. The +.BR nfsref (8) +command operates on whatever junction contents are available. +.SH EXAMPLES +Suppose you have two file servers, +.I top.example.net +and +.IR home.example.net . +You want all your clients to mount +.I top.example.net:/ +and then see the files under +.I home.example.net:/ +automatically in +.IR top:/home . +.P +On +.IR top.example.net , +you might issue this command as root: +.RS +.sp +# mkdir /home +.br +# nfsref --type=nfs-basic add /home home.example.net / +.br +Created junction /home. +.sp +.RE +.SH FILES +.TP +.I /etc/exports +NFS server export table +.SH "SEE ALSO" +.BR exports (5) +.sp +RFC 5661 for a description of NFS version 4 referrals +.SH "AUTHOR" +Chuck Lever <chuck.lever@oracle.com> |