mount(8nfs)															       mount(8nfs)

Name
       mount, umount - mount and unmount a Network File System (NFS)

Syntax
       /etc/mount [ -t nfs -f -r -v ] [ options ] device directory

       /etc/umount [ -v ] directory

Description
       The  command  allows  you  to  mount  a file system or directory onto a directory.  Once a file system or directory has been mounted, it is
       treated as a file system.

       The argument device can have one of the following forms:

	      host:remote_name

	      remote_name@host

       The remote_name is the name of a file system or subtree of a file system that has been exported by host.  The file directory must exist and
       must be a directory.  It becomes the name of the newly mounted file system.

       General users can mount file systems with certain restrictions in addition to those listed in

       The command unmounts the remote file system that was previously mounted on the specified directory.

Options
       See the reference page for a description of the -t option.

       -f	   Fast  unmount.   The  -f  option  has no meaning for local file systems and directories.  However, for remote file system types
		   (such as NFS), the -f option causes the client to unmount the remotely mounted file systems and directories	without  notifying
		   the server.	This can avoid the delay of waiting for acknowledgment from a server that is down.

       -r	   Indicates that the file system is to be mounted read only.

       -v	   Tells what did or did not happen.  (Verbose flag)

       -o options  Specifies options as a sequence of words, separated by commas, from the list that follows.  The default options are as follows:
		   rw,hard,intr,retry=10,000,timeo=11,retrans=4, 
		   port=NFS_PORT,pgthresh=64
		   Defaults for rsize and wsize are set by the kernel.	The NFS options are as follows:

		   bg		 If the first mount attempt fails, retry the mount in the background the number of times specified (the default is
				 10,000 times).

		   hard 	 Retry the NFS operation (not the mount) request until server responds.  The hard option  applies  after  the  has
				 succeeded.  Use the hard option when mounting (read-write) file systems.

		   intr 	 Allow hard mounted file system operations to be interrupted.

		   nintr	 Disallow hard mounted file system operations from being interrupted.

		   noexec	 Binaries cannot be executed from this file system.

		   nosuid	 The and programs can not be executed from this file system.

		   pgthresh=##	 Set the paging threshold for this file system in kilobytes.

		   port=n	 Set server IP port number to n.

		   retrans=n	 Set number of NFS operation retransmissions (not the mount) to n.  The retrans= option applies after the has suc-
				 ceeded.

		   retry=n	 Set number of mount failure retries to n.  The retry= option applies to the command, itself.

		   ro		 Read-only.

		   rsize=n	 Set read buffer size to n bytes.

		   rw		 Read/write.

		   soft 	 Return an error if the server does not respond to the NFS operation (not the mount)  request.	 The  soft  option
				 applies after the has succeeded.  Do not use the soft option to mount (read-write) file systems.

		   timeo=n	 Set NFS timeout to n tenths of a second.

		   wsize=n	 Set write buffer size to n bytes.

		   The	following  options  affect  how  quickly  you  see  updates to a file or directory that has been modified by another host.
		   Increasing these values will give you slightly better performance.  Decreasing these values decreases the time it takes for you
		   to  see  modifications  made  on  another host.  If you are the only modifier of files under this mount point, you can increase
		   these values.

		   acdirmin=n	 Hold cached directory attributes for at least n seconds.  The default is 30 seconds.

		   acdirmax=n	 Hold cached directory attributes for no more than n seconds.  The default  is	60  seconds.   The  maximum  value
				 allowed is 3600.

		   acregmin=n	 Hold cached file attributes for at least n seconds.  The default is 3 seconds.

		   acregmax=n	 Hold cached file attributes for no more than n seconds.  The default is 60 seconds.  The maximum value allowed is
				 3600.

		   actimeo=n	 Set all four attributes cache timeout values to n.

		   noac 	 Do not set attribute caching.	This is equivalent to actimeo=0.

       The option causes to run in the background if the server's daemon does not respond.  The command attempts each request retry=n times before
       giving  up.   Once  the file system is mounted, each NFS request made in the kernel waits timeo=n tenths of a second for a response.  If no
       response arrives, the time-out is multiplied by 2 and the request is retransmitted.

       When retrans=n retransmissions have been sent with no reply, a soft mounted file system returns an error on the request and a hard  mounted
       file  system  retries the request.  If a hard mounted file system was mounted with the option, an operation within that file system that is
       retrying (for example, the server is down) can be interrupted.  File systems that are mounted (read-write) should use the hard option.  The
       number  of bytes in a read or write request can be set with the and options. The values for and must be between 512 and 8192, and be a mul-
       tiple of 512.

       The option for is:

       -v     Tells what did or did not happen.  (Verbose flag)

Restrictions
       If the directory on which a file system is to be mounted is a symbolic link, the file system is mounted on the directory to which the  sym-
       bolic link refers, rather than being mounted on top of the symbolic link itself.

       The and commands should only be invoked by the and commands.  It is recommended that users (and superusers) do not invoke the and commands.
       An exception to this rule is the use of the -b command in the file. The -b command broadcasts a message informing  NFS  servers	that  this
       machine	no  longer has any NFS filesystems mounted. This is done in case the machine had crashed while it had NFS filesystems mounted. The
       servers use this information to clean up their tables. The command automatically adds the -b line to the file on NFS client systems.

Examples
       The command invokes to do its work.  A sample command is:

	    # mount -t nfs -o hard,pgthresh=100 server:/usr /usr

       To mount the remote file system onto the local directory with 1k transfer size, type:

	    # mount -t nfs -o rsize=1024,wsize=1024 serv:/usr/src /mnt

       To mount the remote directory onto the local directory type:

	    # mount -t nfs serv:/usr/src/code /usr/src

       To hard mount a remote file system called onto the local directory type:

	    # mount -t nfs -o hard serv:/usr/src /usr/src

Files
       File system information file

       NFS-specific mount program

       NFS-specific unmount program

See Also
       getmnt(2), mount(2), fstab(5), exports(5nfs), mount(8), umount(8), mountd(8nfs), rmtab(5nfs), nfssetup(8nfs)

																       mount(8nfs)