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Based on kernel version 2.6.34. Page generated on 2010-05-31 16:02 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://xcpu.org/papers/xcpu-talk.pdf
22		* KVMFS: control file system for KVM
23			http://xcpu.org/papers/kvmfs.pdf
24		* CellFS: A New Programming Model for the Cell BE
25			http://xcpu.org/papers/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	For server running on QEMU host with virtio transport:
41	
42		mount -t 9p -o trans=virtio <mount_tag> /mnt/9
43	
44	where mount_tag is the tag associated by the server to each of the exported
45	mount points. Each 9P export is seen by the client as a virtio device with an
46	associated "mount_tag" property. Available mount tags can be
47	seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
48	
49	OPTIONS
50	=======
51	
52	  trans=name	select an alternative transport.  Valid options are
53	  		currently:
54				unix 	- specifying a named pipe mount point
55				tcp	- specifying a normal TCP/IP connection
56				fd   	- used passed file descriptors for connection
57	                                (see rfdno and wfdno)
58				virtio	- connect to the next virtio channel available
59					(from QEMU with trans_virtio module)
60				rdma	- connect to a specified RDMA channel
61	
62	  uname=name	user name to attempt mount as on the remote server.  The
63	  		server may override or ignore this value.  Certain user
64			names may require authentication.
65	
66	  aname=name	aname specifies the file tree to access when the server is
67	  		offering several exported file systems.
68	
69	  cache=mode	specifies a caching policy.  By default, no caches are used.
70				loose = no attempts are made at consistency,
71	                                intended for exclusive, read-only mounts
72				fscache = use FS-Cache for a persistent, read-only
73					cache backend.
74	
75	  debug=n	specifies debug level.  The debug level is a bitmask.
76				0x01  = display verbose error messages
77				0x02  = developer debug (DEBUG_CURRENT)
78				0x04  = display 9p trace
79				0x08  = display VFS trace
80				0x10  = display Marshalling debug
81				0x20  = display RPC debug
82				0x40  = display transport debug
83				0x80  = display allocation debug
84				0x100 = display protocol message debug
85				0x200 = display Fid debug
86				0x400 = display packet debug
87				0x800 = display fscache tracing debug
88	
89	  rfdno=n	the file descriptor for reading with trans=fd
90	
91	  wfdno=n	the file descriptor for writing with trans=fd
92	
93	  maxdata=n	the number of bytes to use for 9p packet payload (msize)
94	
95	  port=n	port to connect to on the remote server
96	
97	  noextend	force legacy mode (no 9p2000.u or 9p2000.L semantics)
98	
99	  version=name	Select 9P protocol version. Valid options are:
100				9p2000          - Legacy mode (same as noextend)
101				9p2000.u        - Use 9P2000.u protocol
102				9p2000.L        - Use 9P2000.L protocol
103	
104	  dfltuid	attempt to mount as a particular uid
105	
106	  dfltgid	attempt to mount with a particular gid
107	
108	  afid		security channel - used by Plan 9 authentication protocols
109	
110	  nodevmap	do not map special files - represent them as normal files.
111	  		This can be used to share devices/named pipes/sockets between
112			hosts.  This functionality will be expanded in later versions.
113	
114	  access	there are three access modes.
115				user  = if a user tries to access a file on v9fs
116				        filesystem for the first time, v9fs sends an
117				        attach command (Tattach) for that user.
118					This is the default mode.
119				<uid> = allows only user with uid=<uid> to access
120					the files on the mounted filesystem
121				any   = v9fs does single attach and performs all
122					operations as one user
123	
124	  cachetag	cache tag to use the specified persistent cache.
125			cache tags for existing cache sessions can be listed at
126			/sys/fs/9p/caches. (applies only to cache=fscache)
127	
128	RESOURCES
129	=========
130	
131	Our current recommendation is to use Inferno (http://www.vitanuova.com/inferno)
132	as the 9p server.  You can start a 9p server under Inferno by issuing the
133	following command:
134	   ; styxlisten -A tcp!*!564 export '#U*'
135	
136	The -A specifies an unauthenticated export.  The 564 is the port # (you may
137	have to choose a higher port number if running as a normal user).  The '#U*'
138	specifies exporting the root of the Linux name space.  You may specify a
139	subset of the namespace by extending the path: '#U*'/tmp would just export
140	/tmp.  For more information, see the Inferno manual pages covering styxlisten
141	and export.
142	
143	A Linux version of the 9p server is now maintained under the npfs project
144	on sourceforge (http://sourceforge.net/projects/npfs).  The currently
145	maintained version is the single-threaded version of the server (named spfs)
146	available from the same SVN repository.
147	
148	There are user and developer mailing lists available through the v9fs project
149	on sourceforge (http://sourceforge.net/projects/v9fs).
150	
151	A stand-alone version of the module (which should build for any 2.6 kernel)
152	is available via (http://github.com/ericvh/9p-sac/tree/master)
153	
154	News and other information is maintained on SWiK (http://swik.net/v9fs)
155	and the Wiki (http://sf.net/apps/mediawiki/v9fs/index.php).
156	
157	Bug reports may be issued through the kernel.org bugzilla 
158	(http://bugzilla.kernel.org)
159	
160	For more information on the Plan 9 Operating System check out
161	http://plan9.bell-labs.com/plan9
162	
163	For information on Plan 9 from User Space (Plan 9 applications and libraries
164	ported to Linux/BSD/OSX/etc) check out http://swtch.com/plan9
165	
166	
167	STATUS
168	======
169	
170	The 2.6 kernel support is working on PPC and x86.
171	
172	PLEASE USE THE KERNEL BUGZILLA TO REPORT PROBLEMS. (http://bugzilla.kernel.org)
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