From: Chuck Lever Subject: [PATCH 07/15] nfs(5) man page: Add new section for -t nfs4 mount options Date: Mon, 05 Nov 2007 20:03:23 -0500 Message-ID: <20071106010323.5037.58741.stgit@ellison.1015granger.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: nfs@lists.sourceforge.net To: steved@redhat.com Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1IpCqi-0004f1-Fu for nfs@lists.sourceforge.net; Mon, 05 Nov 2007 17:03:24 -0800 Received: from flpi102.sbcis.sbc.com ([207.115.20.71] helo=flpi102.prodigy.net) by mail.sourceforge.net with esmtp (Exim 4.44) id 1IpCqn-0004QJ-OT for nfs@lists.sourceforge.net; Mon, 05 Nov 2007 17:03:30 -0800 List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net Collect mount options for the "nfs4" file system type in their own section, clarify the descriptions of each option, and use conventional man page typography. Signed-off-by: Chuck Lever --- utils/mount/nfs.man | 248 ++++++++++++++------------------------------------- 1 files changed, 70 insertions(+), 178 deletions(-) diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man index 98d282e..9cb673a 100644 --- a/utils/mount/nfs.man +++ b/utils/mount/nfs.man @@ -552,191 +552,83 @@ If this option is not specified, the NFS client uses READDIRPLUS requests on NFS version 3 mounts to read small directories. Some applications perform better if the client uses only READDIR requests for all directories. -.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 +.SS "Valid options for the nfs4 file system type" +Use these options, along with the options in the first subsection above, +for mounting the +.B nfs4 +file system type. +.TP 1.5i +.BI proto= netid +The transport protocol used by the RPC client +to transmit requests to the NFS server for this mount point. +The value of +.I netid +can be either +.B 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. +.BR tcp . +All NFS version 4 servers are required to support TCP, +so if this mount option is not specified, +the default transport protocol for NFS version 4 is TCP. +See the TRANSPORT METHODS section for more details. .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. +.BI port= n +The numeric value of the server's NFS service port. +If the server's NFS service is not available on the specified port, +the mount request fails. +If this mount option is not specified, +the NFS client uses the standard NFS port number of 2049 +without first checking the server's rpcbind service. +This allows an NFS version 4 client to contact an NFS version 4 +server through a firewall that may block rpcbind requests. +If the specified port value is 0, +then the NFS client uses the NFS service port number +advertised by the server's rpcbind service. +If the server's rpcbind service is not available, +the server's NFS service is not registered with its rpcbind service, +or the server's NFS service is not available on the advertised port, +the mount request fails. .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.n.n.n -Specifies a single IPv4 address in dotted-quad form that -the NFS client advertises to allow servers to perform -NFSv4 callback requests against files on this mount point. -If the server is not able to establish callback connections -to clients, performance may degrade, or accesses to -files may temporarily hang. +.BR intr " / " nointr +Selects whether to allow signals to interrupt file operations +on this mount point. +When a system call is interrupted while an NFS operation is outstanding, +the system call returns EINTR. +If the +.B intr +option is not specified, signals can interrupt NFS file operations. +Using the +.B intr +option is preferred to using the +.B soft +option because it is significantly less likely to result in data corruption. +.TP 1.5i +.BR cto " / " nocto +Selects whether to use close-to-open cache coherency semantics +for NFS directories on this mount point. +If this option is not specified, +the default is to use close-to-open cache coherency +semantics for directories. +File data caching behavior is not affected by this option. +The DATA AND METADATA COHERENCY section discusses +the behavior of this option in more detail. +.TP 1.5i +.BI clientaddr= n.n.n.n +Specifies a single IPv4 address in dotted-quad form +that the NFS client advertises to allow servers +to perform NFS version 4 callback requests +against files on this mount point. +If the server is not able to establish callback connections to clients, +performance may degrade, or accesses to files may temporarily hang. .IP If this option is not specified, the .BR mount (8) -command attempts to discover an appropriate callback -address automatically. +command attempts to discover an appropriate callback address automatically. The automatic discovery process is not perfect, however. -In the presence of multiple client network interfaces, special -routing policies, or atypical network topologies, the exact -address to use for callbacks may be nontrivial to determine, -and should be explicitly set using this mount option. -.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. -.TP 1.5i -.I nosharecache -As of kernel 2.6.18, it is no longer possible to mount the same -same filesystem with different mount options to a new mountpoint. -It was deemed unsafe to do so, since cached data cannot be shared -between the two mountpoints. In consequence, files or directories -that were common to both mountpoint subtrees could often be seen to -be out of sync following an update. -.br -This option allows administrators to select the pre-2.6.18 behaviour, -permitting the same filesystem to be mounted with different mount -options. -.br -.B Beware: -Use of this option is not recommended unless you are certain that there -are no hard links or subtrees of this mountpoint that are mounted -elsewhere. -.P -All of the non-value options have corresponding nooption forms. -For example, nointr means don't allow file operations to be -interrupted. +In the presence of multiple client network interfaces, +special routing policies, +or atypical network topologies, +the exact address to use for callbacks may be nontrivial to determine. .SH FILES .I /etc/fstab .SH "SEE ALSO" ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. 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