X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fmount%2Fnfs.man;h=0c86559f5d08e00009f72e25de87f391e71ebde3;hp=2c0b6878e50147ab666d4e7454ba54c8ddddd740;hb=632650fa1a0b358f9d8d617cfd115a334c4b9b66;hpb=5c4f17a97b1260e9c564ddd9887afaf50a26de9d diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man index 2c0b687..0c86559 100644 --- a/utils/mount/nfs.man +++ b/utils/mount/nfs.man @@ -411,15 +411,15 @@ for mounting the .B nfs file system type. .TP 1.5i -.BI proto= netid -The transport protocol used by the NFS client +.BI proto= transport +The transport the NFS client uses to transmit requests to the NFS server for this mount point. -.I netid +.I transport can be either .B udp or .BR tcp . -Each transport protocol uses different default +Each transport uses different default .B retrans and .B timeo @@ -489,6 +489,30 @@ or the server's mountd service is not available on the advertised port. This option can be used when mounting an NFS server through a firewall that blocks the rpcbind protocol. .TP 1.5i +.BI mountproto= transport +The transport the NFS client uses +to transmit requests to the NFS server's mountd service when performing +this mount request, and when later unmounting this mount point. +.I transport +can be either +.B udp +or +.BR tcp . +.IP +This option can be used when mounting an NFS server +through a firewall that blocks a particular transport. +When used in combination with the +.B proto +option, different transports for mountd requests and NFS requests +can be specified. +If the server's mountd service is not available via the specified +transport, the mount request fails. +Refer to the TRANSPORT METHODS section for more on how the +.B mountproto +mount option interacts with the +.B proto +mount option. +.TP 1.5i .BI mounthost= name The hostname of the host running mountd. If this option is not specified, the @@ -619,10 +643,10 @@ for mounting the .B nfs4 file system type. .TP 1.5i -.BI proto= netid -The transport protocol used by the NFS client +.BI proto= transport +The transport the NFS client uses to transmit requests to the NFS server for this mount point. -.I netid +.I transport can be either .B udp or @@ -812,6 +836,84 @@ and .B wsize can safely be allowed to default to the largest values supported by both client and server, independent of the network's MTU size. +.SS "Using the mountproto mount option" +This section applies only to NFS version 2 and version 3 mounts +since NFS version 4 does not use a separate protocol for mount +requests. +.P +The Linux NFS client can use a different transport for +contacting an NFS server's rpcbind service, its mountd service, +its Network Lock Manager (NLM) service, and its NFS service. +The exact transports employed by the Linux NFS client for +each mount point depends on the settings of the transport +mount options, which include +.BR proto , +.BR mountproto , +.BR udp ", and " tcp . +.P +The client sends Network Status Manager (NSM) notifications +via UDP no matter what transport options are specified, but +listens for server NSM notifications on both UDP and TCP. +The NFS Access Control List (NFSACL) protocol shares the same +transport as the main NFS service. +.P +If no transport options are specified, the Linux NFS client +uses UDP to contact the server's mountd service, and TCP to +contact its NLM and NFS services by default. +.P +If the server does not support these transports for these services, the +.BR mount (8) +command attempts to discover what the server supports, and then retries +the mount request once using the discovered transports. +If the server does not advertise any transport supported by the client +or is misconfigured, the mount request fails. +If the +.B bg +option is in effect, the mount command backgrounds itself and continues +to attempt the specified mount request. +.P +When the +.B proto +option, the +.B udp +option, or the +.B tcp +option is specified but the +.B mountproto +option is not, the specified transport is used to contact +both the server's mountd service and for the NLM and NFS services. +.P +If the +.B mountproto +option is specified but none of the +.BR proto ", " udp " or " tcp +options are specified, then the specified transport is used for the +initial mountd request, but the mount command attempts to discover +what the server supports for the NFS protocol, preferring TCP if +both transports are supported. +.P +If both the +.BR mountproto " and " proto +(or +.BR udp " or " tcp ) +options are specified, then the transport specified by the +.B mountproto +option is used for the initial mountd request, and the transport +specified by the +.B proto +option (or the +.BR udp " or " tcp " options)" +is used for NFS, no matter what order these options appear. +No automatic service discovery is performed if these options are +specified. +.P +If any of the +.BR proto ", " udp ", " tcp ", " +or +.B mountproto +options are specified more than once on the same mount command line, +then the value of the rightmost instance of each of these options +takes effect. .SH "DATA AND METADATA COHERENCE" Some modern cluster file systems provide perfect cache coherence among their clients. @@ -1215,6 +1317,8 @@ such as security negotiation, server referrals, and named attributes. .BR umount.nfs (5), .BR exports (5), .BR nfsd (8), +.BR sm-notify (8), +.BR rpc.statd (8), .BR rpc.idmapd (8), .BR rpc.gssd (8), .BR rpc.svcgssd (8),