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Documentation / filesystems / 9p.txt

Based on kernel version 2.6.26. Page generated on 2008-07-16 21:12 EST.

1		  	    v9fs: Plan 9 Resource Sharing for Linux
2			    =======================================
3	
4	ABOUT
5	=====
6	
7	v9fs is a Unix implementation of the Plan 9 9p remote filesystem protocol.
8	
9	This software was originally developed by Ron Minnich <rminnich[AT]sandia[DOT]gov>
10	and Maya Gokhale.  Additional development by Greg Watson
11	<gwatson[AT]lanl[DOT]gov> and most recently Eric Van Hensbergen
12	<ericvh[AT]gmail.com>, Latchesar Ionkov <lucho@ionkov[DOT]net> and Russ Cox
13	<rsc[AT]swtch.com>[DOT]
14	
15	The best detailed explanation of the Linux implementation and applications of
16	the 9p client is available in the form of a USENIX paper:
17	   http://www.usenix.org/events/usenix05/tech/freenix/hensbergen.html
18	
19	Other applications are described in the following papers:
20		* XCPU & Clustering
21			http://www.xcpu.org/xcpu-talk.pdf
22		* KVMFS: control file system for KVM
23			http://www.xcpu.org/kvmfs.pdf
24		* CellFS: A New ProgrammingModel for the Cell BE
25			http://www.xcpu.org/cellfs-talk.pdf
26		* PROSE I/O: Using 9p to enable Application Partitions
27			http://plan9.escet.urjc.es/iwp9/cready/PROSE_iwp9_2006.pdf
28	
29	USAGE
30	=====
31	
32	For remote file server:
33	
34		mount -t 9p 10.10.1.2 /mnt/9
35	
36	For Plan 9 From User Space applications (http://swtch.com/plan9)
37	
38		mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
39	
40	OPTIONS
41	=======
42	
43	  trans=name	select an alternative transport.  Valid options are
44	  		currently:
45				unix 	- specifying a named pipe mount point
46				tcp	- specifying a normal TCP/IP connection
47				fd   	- used passed file descriptors for connection
48	                                (see rfdno and wfdno)
49				virtio	- connect to the next virtio channel available
50					(from lguest or KVM with trans_virtio module)
51	
52	  uname=name	user name to attempt mount as on the remote server.  The
53	  		server may override or ignore this value.  Certain user
54			names may require authentication.
55	
56	  aname=name	aname specifies the file tree to access when the server is
57	  		offering several exported file systems.
58	
59	  cache=mode	specifies a caching policy.  By default, no caches are used.
60				loose = no attempts are made at consistency,
61	                                intended for exclusive, read-only mounts
62	
63	  debug=n	specifies debug level.  The debug level is a bitmask.
64	  			0x01 = display verbose error messages
65				0x02 = developer debug (DEBUG_CURRENT)
66				0x04 = display 9p trace
67				0x08 = display VFS trace
68				0x10 = display Marshalling debug
69				0x20 = display RPC debug
70				0x40 = display transport debug
71				0x80 = display allocation debug
72	
73	  rfdno=n	the file descriptor for reading with trans=fd
74	
75	  wfdno=n	the file descriptor for writing with trans=fd
76	
77	  maxdata=n	the number of bytes to use for 9p packet payload (msize)
78	
79	  port=n	port to connect to on the remote server
80	
81	  noextend	force legacy mode (no 9p2000.u semantics)
82	
83	  dfltuid	attempt to mount as a particular uid
84	
85	  dfltgid	attempt to mount with a particular gid
86	
87	  afid		security channel - used by Plan 9 authentication protocols
88	
89	  nodevmap	do not map special files - represent them as normal files.
90	  		This can be used to share devices/named pipes/sockets between
91			hosts.  This functionality will be expanded in later versions.
92	
93	  access	there are three access modes.
94				user  = if a user tries to access a file on v9fs
95				        filesystem for the first time, v9fs sends an
96				        attach command (Tattach) for that user.
97					This is the default mode.
98				<uid> = allows only user with uid=<uid> to access
99					the files on the mounted filesystem
100				any   = v9fs does single attach and performs all
101					operations as one user
102	
103	RESOURCES
104	=========
105	
106	Our current recommendation is to use Inferno (http://www.vitanuova.com/inferno)
107	as the 9p server.  You can start a 9p server under Inferno by issuing the
108	following command:
109	   ; styxlisten -A tcp!*!564 export '#U*'
110	
111	The -A specifies an unauthenticated export.  The 564 is the port # (you may
112	have to choose a higher port number if running as a normal user).  The '#U*'
113	specifies exporting the root of the Linux name space.  You may specify a
114	subset of the namespace by extending the path: '#U*'/tmp would just export
115	/tmp.  For more information, see the Inferno manual pages covering styxlisten
116	and export.
117	
118	A Linux version of the 9p server is now maintained under the npfs project
119	on sourceforge (http://sourceforge.net/projects/npfs).  The currently
120	maintained version is the single-threaded version of the server (named spfs)
121	available from the same CVS repository.
122	
123	There are user and developer mailing lists available through the v9fs project
124	on sourceforge (http://sourceforge.net/projects/v9fs).
125	
126	News and other information is maintained on SWiK (http://swik.net/v9fs).
127	
128	Bug reports may be issued through the kernel.org bugzilla 
129	(http://bugzilla.kernel.org)
130	
131	For more information on the Plan 9 Operating System check out
132	http://plan9.bell-labs.com/plan9
133	
134	For information on Plan 9 from User Space (Plan 9 applications and libraries
135	ported to Linux/BSD/OSX/etc) check out http://swtch.com/plan9
136	
137	
138	STATUS
139	======
140	
141	The 2.6 kernel support is working on PPC and x86.
142	
143	PLEASE USE THE KERNEL BUGZILLA TO REPORT PROBLEMS. (http://bugzilla.kernel.org)
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