From 16db99b56a532bf56fa27618a6ef30763cd9006f Mon Sep 17 00:00:00 2001 From: Neil Brown Date: Fri, 16 Mar 2007 16:25:55 +1100 Subject: [PATCH] Add nfs.5 man page --- utils/mount/Makefile.am | 13 +- utils/mount/nfs.man | 456 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 468 insertions(+), 1 deletion(-) create mode 100644 utils/mount/nfs.man diff --git a/utils/mount/Makefile.am b/utils/mount/Makefile.am index 500c429..cdd78d8 100644 --- a/utils/mount/Makefile.am +++ b/utils/mount/Makefile.am @@ -5,9 +5,10 @@ sbindir = /sbin man8_MANS = mount.nfs.man umount.nfs.man +man5_MANS = nfs.man sbin_PROGRAMS = mount.nfs -EXTRA_DIST = nfsmount.x $(man8_MANS) +EXTRA_DIST = nfsmount.x $(man8_MANS) $(man5_MANS) mount_nfs_SOURCES = mount.c nfsmount.c nfs4mount.c nfsumount.c \ mount_constants.h nfs4_mount.h nfs_mount4.h @@ -32,6 +33,11 @@ install-man-links: inst=`echo $$m | sed -e 's/man$$/8/'`; \ rm -f $$inst ; \ done) + (cd $(DESTDIR)$(man5dir) && \ + for m in $(man5_MANS) $(dist_man5_MANS) $(nodist_man5_MANS); do \ + inst=`echo $$m | sed -e 's/man$$/5/'`; \ + rm -f $$inst ; \ + done) uninstall-man-links: (cd $(DESTDIR)$(man8dir) && \ @@ -39,4 +45,9 @@ uninstall-man-links: inst=`echo $$m | sed -e 's/man$$/8/'`; \ rm -f $$inst ; \ done) + (cd $(DESTDIR)$(man5dir) && \ + for m in $(man5_MANS) $(dist_man5_MANS) $(nodist_man5_MANS); do \ + inst=`echo $$m | sed -e 's/man$$/5/'`; \ + rm -f $$inst ; \ + done) diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man new file mode 100644 index 0000000..ad44d71 --- /dev/null +++ b/utils/mount/nfs.man @@ -0,0 +1,456 @@ +.\" nfs.5 "Rick Sladkey" +.\" Wed Feb 8 12:52:42 1995, faith@cs.unc.edu: updates for Ross Biro's +.\" patches. " +.TH NFS 5 "20 November 1993" "Linux 0.99" "Linux Programmer's Manual" +.SH NAME +nfs \- nfs and nfs4 fstab format and options +.SH SYNOPSIS +.B /etc/fstab +.SH DESCRIPTION +The +.I fstab +file contains information about which filesystems +to mount where and with what options. +For NFS mounts, it contains the server name and +exported server directory to mount from, +the local directory that is the mount point, +and the NFS specific options that control +the way the filesystem is mounted. +.P +Three different versions of the NFS protocol are +supported by the Linux NFS client: +NFS version 2, NFS version 3, and NFS version 4. +To mount via NFS version 2, use the +.BR nfs +file system type and specify +.BR nfsvers=2 . +Version 2 is the default protocol version for the +.BR nfs +file system type when +.BR nfsvers= +is not specified on the mount command. +To mount via NFS version 3, use the +.BR nfs +file system type and specify +.BR nfsvers=3 . +To mount via NFS version 4, use the +.BR nfs4 +file system type. +The +.BR nfsvers= +keyword is not supported for the +.BR nfs4 +file system type. +.P +These file system types share similar mount options; +the differences are listed below. +.P +Here is an example from an \fI/etc/fstab\fP file for an NFSv2 mount +over UDP. +.sp +.nf +.ta 2.5i +0.75i +0.75i +1.0i +server:/usr/local/pub /pub nfs rsize=32768,wsize=32768,timeo=14,intr +.fi +.P +Here is an example for an NFSv4 mount over TCP using Kerberos +5 mutual authentication. +.sp +.nf +.ta 2.5i +0.75i +0.75i +1.0i +server:/usr/local/pub /pub nfs4 proto=tcp,sec=krb5,hard,intr +.fi +.DT +.SS Options for the nfs file system type +.TP 1.5i +.I rsize=n +The number of bytes NFS uses when reading files from an NFS server. +The rsize is negotiated between the server and client to determine +the largest block size that both can support. +The value specified by this option is the maximum size that could +be used; however, the actual size used may be smaller. +Note: Setting this size to a value less than the largest supported +block size will adversely affect performance. +.TP 1.5i +.I wsize=n +The number of bytes NFS uses when writing files to an NFS server. +The wsize is negotiated between the server and client to determine +the largest block size that both can support. +The value specified by this option is the maximum size that could +be used; however, the actual size used may be smaller. +Note: Setting this size to a value less than the largest supported +block size will adversely affect performance. +.TP 1.5i +.I timeo=n +The value in tenths of a second before sending the +first retransmission after an RPC timeout. +The default value is 7 tenths of a second. After the first timeout, +the timeout is doubled after each successive timeout until a maximum +timeout of 60 seconds is reached or the enough retransmissions +have occured to cause a major timeout. Then, if the filesystem +is hard mounted, each new timeout cascade restarts at twice the +initial value of the previous cascade, again doubling at each +retransmission. The maximum timeout is always 60 seconds. +Better overall performance may be achieved by increasing the +timeout when mounting on a busy network, to a slow server, or through +several routers or gateways. +.TP 1.5i +.I retrans=n +The number of minor timeouts and retransmissions that must occur before +a major timeout occurs. The default is 3 timeouts. When a major timeout +occurs, the file operation is either aborted or a "server not responding" +message is printed on the console. +.TP 1.5i +.I acregmin=n +The minimum time in seconds that attributes of a regular file should +be cached before requesting fresh information from a server. +The default is 3 seconds. +.TP 1.5i +.I acregmax=n +The maximum time in seconds that attributes of a regular file can +be cached before requesting fresh information from a server. +The default is 60 seconds. +.TP 1.5i +.I acdirmin=n +The minimum time in seconds that attributes of a directory should +be cached before requesting fresh information from a server. +The default is 30 seconds. +.TP 1.5i +.I acdirmax=n +The maximum time in seconds that attributes of a directory can +be cached before requesting fresh information from a server. +The default is 60 seconds. +.TP 1.5i +.I actimeo=n +Using actimeo sets all of +.I acregmin, +.I acregmax, +.I acdirmin, +and +.I acdirmax +to the same value. +There is no default value. +.TP 1.5i +.I retry=n +The number of minutes to retry an NFS mount operation +in the foreground or background before giving up. +The default value for forground mounts is 2 minutes. +The default value for background mounts is 10000 minutes, +which is roughly one week. +.TP 1.5i +.I namlen=n +When an NFS server does not support version two of the +RPC mount protocol, this option can be used to specify +the maximum length of a filename that is supported on +the remote filesystem. This is used to support the +POSIX pathconf functions. The default is 255 characters. +.TP 1.5i +.I port=n +The numeric value of the port to connect to the NFS server on. +If the port number is 0 (the default) then query the +remote host's portmapper for the port number to use. +If the remote host's NFS daemon is not registered with +its portmapper, the standard NFS port number 2049 is +used instead. +.TP 1.5i +.I mountport=n +The numeric value of the +.B mountd +port. +.TP 1.5i +.I mounthost=name +The name of the host running +.B mountd . +.TP 1.5i +.I mountprog=n +Use an alternate RPC program number to contact the +mount daemon on the remote host. This option is useful +for hosts that can run multiple NFS servers. +The default value is 100005 which is the standard RPC +mount daemon program number. +.TP 1.5i +.I mountvers=n +Use an alternate RPC version number to contact the +mount daemon on the remote host. This option is useful +for hosts that can run multiple NFS servers. +The default value depends on which kernel you are using. +.TP 1.5i +.I nfsprog=n +Use an alternate RPC program number to contact the +NFS daemon on the remote host. This option is useful +for hosts that can run multiple NFS servers. +The default value is 100003 which is the standard RPC +NFS daemon program number. +.TP 1.5i +.I nfsvers=n +Use an alternate RPC version number to contact the +NFS daemon on the remote host. This option is useful +for hosts that can run multiple NFS servers. +The default value depends on which kernel you are using. +.TP 1.5i +.I vers=n +vers is an alternative to nfsvers and is compatible with +many other operating systems. +.TP 1.5i +.I nolock +Disable NFS locking. Do not start lockd. +This has to be used with some old NFS servers +that don't support locking. +.TP 1.5i +.I bg +If the first NFS mount attempt times out, retry the mount +in the background. +After a mount operation is backgrounded, all subsequent mounts +on the same NFS server will be backgrounded immediately, without +first attempting the mount. +A missing mount point is treated as a timeout, +to allow for nested NFS mounts. +.TP 1.5i +.I fg +If the first NFS mount attempt times out, retry the mount +in the foreground. +This is the complement of the +.I bg +option, and also the default behavior. +.TP 1.5i +.I soft +If an NFS file operation has a major timeout then report an I/O error to +the calling program. +The default is to continue retrying NFS file operations indefinitely. +.TP 1.5i +.I hard +If an NFS file operation has a major timeout then report +"server not responding" on the console and continue retrying indefinitely. +This is the default. +.TP 1.5i +.I intr +If an NFS file operation has a major timeout and it is hard mounted, +then allow signals to interupt the file operation and cause it to +return EINTR to the calling program. The default is to not +allow file operations to be interrupted. +.TP 1.5i +.I posix +Mount the NFS filesystem using POSIX semantics. This allows +an NFS filesystem to properly support the POSIX pathconf +command by querying the mount server for the maximum length +of a filename. To do this, the remote host must support version +two of the RPC mount protocol. Many NFS servers support only +version one. +.TP 1.5i +.I nocto +Suppress the retrieval of new attributes when creating a file. +.TP 1.5i +.I noac +Disable all forms of attribute caching entirely. This extracts a +significant performance penalty but it allows two different NFS clients +to get reasonable results when both clients are actively +writing to a common export on the server. +.TP 1.5i +.I noacl +Disables Access Control List (ACL) processing. +.TP 1.5i +.I sec=mode +Set the security flavor for this mount to "mode". +The default setting is \f3sec=sys\f1, which uses local +unix uids and gids to authenticate NFS operations (AUTH_SYS). +Other currently supported settings are: +\f3sec=krb5\f1, which uses Kerberos V5 instead of local unix uids +and gids to authenticate users; +\f3sec=krb5i\f1, which uses Kerberos V5 for user authentication +and performs integrity checking of NFS operations using secure +checksums to prevent data tampering; and +\f3sec=krb5p\f1, which uses Kerberos V5 for user authentication +and integrity checking, and encrypts NFS traffic to prevent +traffic sniffing (this is the most secure setting). +Note that there is a performance penalty when using integrity +or privacy. +.TP 1.5i +.I tcp +Mount the NFS filesystem using the TCP protocol instead of the +default UDP protocol. Many NFS servers only support UDP. +.TP 1.5i +.I udp +Mount the NFS filesystem using the UDP protocol. This +is the default. +.P +All of the non-value options have corresponding nooption forms. +For example, nointr means don't allow file operations to be +interrupted. +.SS Options for the nfs4 file system type +.TP 1.5i +.I rsize=n +The number of bytes nfs4 uses when reading files from the server. +The rsize is negotiated between the server and client to determine +the largest block size that both can support. +The value specified by this option is the maximum size that could +be used; however, the actual size used may be smaller. +Note: Setting this size to a value less than the largest supported +block size will adversely affect performance. +.TP 1.5i +.I wsize=n +The number of bytes nfs4 uses when writing files to the server. +The wsize is negotiated between the server and client to determine +the largest block size that both can support. +The value specified by this option is the maximum size that could +be used; however, the actual size used may be smaller. +Note: Setting this size to a value less than the largest supported +block size will adversely affect performance. +.TP 1.5i +.I timeo=n +The value in tenths of a second before sending the +first retransmission after an RPC timeout. +The default value depends on whether +.IR proto=udp +or +.IR proto=tcp +is in effect (see below). +The default value for UDP is 7 tenths of a second. +The default value for TCP is 60 seconds. +After the first timeout, +the timeout is doubled after each successive timeout until a maximum +timeout of 60 seconds is reached or the enough retransmissions +have occured to cause a major timeout. Then, if the filesystem +is hard mounted, each new timeout cascade restarts at twice the +initial value of the previous cascade, again doubling at each +retransmission. The maximum timeout is always 60 seconds. +.TP 1.5i +.I retrans=n +The number of minor timeouts and retransmissions that must occur before +a major timeout occurs. The default is 5 timeouts for +.IR proto=udp +and 2 timeouts for +.IR proto=tcp . +When a major timeout +occurs, the file operation is either aborted or a "server not responding" +message is printed on the console. +.TP 1.5i +.I acregmin=n +The minimum time in seconds that attributes of a regular file should +be cached before requesting fresh information from a server. +The default is 3 seconds. +.TP 1.5i +.I acregmax=n +The maximum time in seconds that attributes of a regular file can +be cached before requesting fresh information from a server. +The default is 60 seconds. +.TP 1.5i +.I acdirmin=n +The minimum time in seconds that attributes of a directory should +be cached before requesting fresh information from a server. +The default is 30 seconds. +.TP 1.5i +.I acdirmax=n +The maximum time in seconds that attributes of a directory can +be cached before requesting fresh information from a server. +The default is 60 seconds. +.TP 1.5i +.I actimeo=n +Using actimeo sets all of +.I acregmin, +.I acregmax, +.I acdirmin, +and +.I acdirmax +to the same value. +There is no default value. +.TP 1.5i +.I retry=n +The number of minutes to retry an NFS mount operation +in the foreground or background before giving up. +The default value for forground mounts is 2 minutes. +The default value for background mounts is 10000 minutes, +which is roughly one week. +.TP 1.5i +.I port=n +The numeric value of the port to connect to the NFS server on. +If the port number is 0 (the default) then query the +remote host's portmapper for the port number to use. +If the remote host's NFS daemon is not registered with +its portmapper, the standard NFS port number 2049 is +used instead. +.TP 1.5i +.I proto=n +Mount the NFS filesystem using a specific network protocol +instead of the default UDP protocol. +Many NFS version 4 servers only support TCP. +Valid protocol types are +.IR udp +and +.IR tcp . +.TP 1.5i +.I clientaddr=n +On a multi-homed client, this +causes the client to use a specific callback address when +communicating with an NFS version 4 server. +This option is currently ignored. +.TP 1.5i +.I sec=mode +Same as \f3sec=mode\f1 for the nfs filesystem type (see above). +.TP 1.5i +.I bg +If an NFS mount attempt times out, retry the mount +in the background. +After a mount operation is backgrounded, all subsequent mounts +on the same NFS server will be backgrounded immediately, without +first attempting the mount. +A missing mount point is treated as a timeout, +to allow for nested NFS mounts. +.TP 1.5i +.I fg +If the first NFS mount attempt times out, retry the mount +in the foreground. +This is the complement of the +.I bg +option, and also the default behavior. +.TP 1.5i +.I soft +If an NFS file operation has a major timeout then report an I/O error to +the calling program. +The default is to continue retrying NFS file operations indefinitely. +.TP 1.5i +.I hard +If an NFS file operation has a major timeout then report +"server not responding" on the console and continue retrying indefinitely. +This is the default. +.TP 1.5i +.I intr +If an NFS file operation has a major timeout and it is hard mounted, +then allow signals to interupt the file operation and cause it to +return EINTR to the calling program. The default is to not +allow file operations to be interrupted. +.TP 1.5i +.I nocto +Suppress the retrieval of new attributes when creating a file. +.TP 1.5i +.I noac +Disable attribute caching, and force synchronous writes. +This extracts a +server performance penalty but it allows two different NFS clients +to get reasonable good results when both clients are actively +writing to common filesystem on the server. +.P +All of the non-value options have corresponding nooption forms. +For example, nointr means don't allow file operations to be +interrupted. +.SH FILES +.I /etc/fstab +.SH "SEE ALSO" +.BR fstab "(5), " mount "(8), " umount "(8), " exports (5) +.SH AUTHOR +"Rick Sladkey" +.SH BUGS +The posix, and nocto options are parsed by mount +but currently are silently ignored. +.P +The tcp and namlen options are implemented but are not currently +supported by the Linux kernel. +.P +The umount command should notify the server +when an NFS filesystem is unmounted. +.P +Checking files on NFS filesystem referenced by file descriptors (i.e. the +.BR fcntl +and +.BR ioctl +families of functions) may lead to inconsistent result due to the lack of +consistency check in kernel even if noac is used. -- 2.39.2