e03abc0c96
While cacheing is generally frowned upon in the 9p world, it has its place -- particularly in situations where the remote file system is exclusive and/or read-only. The vacfs views of venti content addressable store are a real-world instance of such a situation. To facilitate higher performance for these workloads (and eventually use the fscache patches), we have enabled a "loose" cache mode which does not attempt to maintain any form of consistency on the page-cache or dcache. This results in over two orders of magnitude performance improvement for cacheable block reads in the Bonnie benchmark. The more aggressive use of the dcache also seems to improve metadata operational performance. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
118 lines
3.9 KiB
Text
118 lines
3.9 KiB
Text
v9fs: Plan 9 Resource Sharing for Linux
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=======================================
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ABOUT
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=====
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v9fs is a Unix implementation of the Plan 9 9p remote filesystem protocol.
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This software was originally developed by Ron Minnich <rminnich@lanl.gov>
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and Maya Gokhale <maya@lanl.gov>. Additional development by Greg Watson
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<gwatson@lanl.gov> and most recently Eric Van Hensbergen
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<ericvh@gmail.com>, Latchesar Ionkov <lucho@ionkov.net> and Russ Cox
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<rsc@swtch.com>.
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USAGE
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=====
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For remote file server:
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mount -t 9p 10.10.1.2 /mnt/9
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For Plan 9 From User Space applications (http://swtch.com/plan9)
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mount -t 9p `namespace`/acme /mnt/9 -o proto=unix,uname=$USER
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OPTIONS
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=======
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proto=name select an alternative transport. Valid options are
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currently:
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unix - specifying a named pipe mount point
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tcp - specifying a normal TCP/IP connection
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fd - used passed file descriptors for connection
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(see rfdno and wfdno)
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uname=name user name to attempt mount as on the remote server. The
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server may override or ignore this value. Certain user
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names may require authentication.
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aname=name aname specifies the file tree to access when the server is
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offering several exported file systems.
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cache=mode specifies a cacheing policy. By default, no caches are used.
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loose = no attempts are made at consistency,
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intended for exclusive, read-only mounts
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debug=n specifies debug level. The debug level is a bitmask.
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0x01 = display verbose error messages
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0x02 = developer debug (DEBUG_CURRENT)
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0x04 = display 9p trace
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0x08 = display VFS trace
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0x10 = display Marshalling debug
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0x20 = display RPC debug
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0x40 = display transport debug
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0x80 = display allocation debug
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rfdno=n the file descriptor for reading with proto=fd
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wfdno=n the file descriptor for writing with proto=fd
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maxdata=n the number of bytes to use for 9p packet payload (msize)
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port=n port to connect to on the remote server
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noextend force legacy mode (no 9p2000.u semantics)
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uid attempt to mount as a particular uid
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gid attempt to mount with a particular gid
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afid security channel - used by Plan 9 authentication protocols
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nodevmap do not map special files - represent them as normal files.
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This can be used to share devices/named pipes/sockets between
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hosts. This functionality will be expanded in later versions.
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RESOURCES
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=========
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Our current recommendation is to use Inferno (http://www.vitanuova.com/inferno)
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as the 9p server. You can start a 9p server under Inferno by issuing the
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following command:
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; styxlisten -A tcp!*!564 export '#U*'
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The -A specifies an unauthenticated export. The 564 is the port # (you may
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have to choose a higher port number if running as a normal user). The '#U*'
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specifies exporting the root of the Linux name space. You may specify a
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subset of the namespace by extending the path: '#U*'/tmp would just export
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/tmp. For more information, see the Inferno manual pages covering styxlisten
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and export.
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A Linux version of the 9p server is now maintained under the npfs project
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on sourceforge (http://sourceforge.net/projects/npfs). There is also a
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more stable single-threaded version of the server (named spfs) available from
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the same CVS repository.
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There are user and developer mailing lists available through the v9fs project
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on sourceforge (http://sourceforge.net/projects/v9fs).
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News and other information is maintained on SWiK (http://swik.net/v9fs).
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Bug reports may be issued through the kernel.org bugzilla
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(http://bugzilla.kernel.org)
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For more information on the Plan 9 Operating System check out
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http://plan9.bell-labs.com/plan9
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For information on Plan 9 from User Space (Plan 9 applications and libraries
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ported to Linux/BSD/OSX/etc) check out http://swtch.com/plan9
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STATUS
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======
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The 2.6 kernel support is working on PPC and x86.
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PLEASE USE THE KERNEL BUGZILLA TO REPORT PROBLEMS. (http://bugzilla.kernel.org)
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