NAME

exportfs, srvfs − network file server plumbing

SYNOPSIS

­exportfs [ ­-asF ] [ ­-r ­root ]

­srvfs [ ­-p ­perm ] ­name ­dir

DESCRIPTION

­Exportfs is a user level file server that allows Plan 9 compute servers, rather than file servers, to export portions of a name space across networks.  The service is started either by the cpu(1) command or by a network listener process.  An initial protocol establishes a root directory for the exported name space. The connection to ­exportfs is then mounted, typically on /mnt/term.  ­Exportfs then acts as a relay file server: operations in the imported file tree are executed on the remote server and the results returned.  This gives the appearance of exporting a name space from a remote machine into a local file tree. 

The ­-r option bypasses the initial protocol, instead immediately serving the namespace rooted at root. The ­-s option is equivalent to ­-r /, but predates ­-r and remains for compatibility. 

The ­-a option instructs ­exportfs to authenticate the user, usually because it is being invoked from a remote machine. 

The ­-F option causes ­exportfs to push the ­fcall line discipline on its network connection.  This option is intended for networks that do not preserve read/write boundaries. 

The ­cpu command uses ­exportfs to serve device files in the terminal.  The import(4) command calls ­exportfs on a remote machine, permitting users to access arbitrary pieces of name space on other systems. 

­Srvfs uses ­exportfs to create a mountable file system from a name space: a subsequent ­mount (see bind(1)) of /srv/name, which is created with mode ­perm (default 0600), will reproduce the name space rooted at dir. One might use ­srvfs to enable mounting of an FTP file system (see ftpfs(4)) in several windows, or to publish a ­/proc (see proc(3)) with a broken process so a remote person may debug the program.

SOURCE

­/sys/src/cmd/exportfs
­/sys/src/cmd/srvfs.c

Plan 9  —  March 27, 2001