1.HTML "Plan 9 — Fourth Edition Release Notes 2.TL 3Plan 9 From Bell Labs 4.br 5Fourth Release Notes 6.br 7April, 2002 8.br 9updated June, 2003 10.LP 11.sp -.4i 12.nf 13.ce 1000 14Copyright © 2002-2003 Lucent Technologies Inc. 15All Rights Reserved 16.sp .2i 17.fi 18.LP 19The fourth release of the Plan 9 operating system from Bell Labs 20packages a major overhaul of the system at every level. 21From the underlying file system protocol, 9P, through the kernel, 22libraries, and applications, almost everything has been modified 23and, in many cases, redesigned or rewritten. 24.LP 25The most significant change is that 9P has been redesigned to address 26a number of shortcomings, most important, its previous inability to handle long 27file names. 28Unfortunately, squeezing long names onto the disks of existing 29file servers is a messy business that we're still grappling with, 30so at the moment 31.I fs (4) 32and 33.I kfs (4) 34can't yet handle long names, 35although they do talk the new protocol. 36(In fact, they 37talk both old and new, as required, to ease transition.) 38In the meantime, there is a workaround \(em 39.I lnfs (4) 40\(em 41and many of the other file servers such as 42.I ramfs (4) 43and 44.I u9fs (4) 45work just fine with long names. 46It's only the old disk-resident file servers 47that don't. 48The new file server 49.I fossil (4) 50handles supports long names and many other features. 51The older servers are now deprecated. 52.LP 53The following is a partial list of the major changes throughout the system. 54.de Xx 55.LP 56\(bu 57.. 58.Xx 59The file system protocol, 9P, has been reworked. 60It now has variable-length names, so it can handle long names 61but also is more compact when handling short ones. 62It uses a different format that is easily parsed, eliminating the need for the old 63.CW aux/fcall 64utility, 65and delegates its authentication duties to an external agent, 66.CW factotum . 67.Xx 68Security has been a focus of attention. 69A new security agent, 70.I factotum (4), 71manages passwords and other secrets and, coupled with a new secure file store 72.I secstore (8), 73enables secure single sign-on. 74.Xx 75.CW Cpu , 76.CW import , 77and 78.CW exportfs 79all encrypt their connections now, and since they use the new 9P they 80also use new network port numbers. 81A new service 82.I aan (1) 83is used by 84.CW import 85to make its network connections more reliable in the face of network outages. 86The old ports still work, through the agency of a protocol conversion filter 87.I srvold9p (4). 88.Xx 89We are phasing out the IL protocol since it doesn't handle long-distance connections 90well (and long-distance networks don't handle it well, either). 91IL is still used by 92.I fs (4) 93but TCP has become the standard protocol for all other services. 94.Xx 95The software for the new network-resident secure block store, 96.I venti (8), 97is included with this distribution. 98The new 99file server 100.I fossil (4) 101uses Venti rather than a WORM as its permanent block repository/backup medium. 102It is still being developed, but is mature enough that a handful of users 103throughout the world are using it as their primary file server. 104.Xx 105The need to handle longer file names triggered a rethinking of the way the 106system handles strings in general. 107The kernel is now more explanatory when it gives an error message and 108more consistent in how it handles strings such as commands to devices. 109The interfaces to many of the system calls, such as 110.I errstr (2) 111and 112.I wait (2) 113all had to change as a result, as did the library interface to read directories, 114.I stat (2) 115and its relatives. 116.Xx 117The formatted I/O package described in 118.I print (2) 119and 120.I fmtinstall (2) 121has been redesigned. 122Although the basic interface is unchanged, it now runs without locks and 123has an internal buffer management mechanism that means 124.CW print 125no longer needs a large on-stack buffer. 126The interface for writing custom print verbs and custom formatted I/O routines 127has also been greatly improved. 128.Xx 129The thread library 130.I thread (2) 131has been completely rewritten. 132The main visible change is that, coupled with the changes to printing, 133.CW threadprint 134is gone; you can just use 135.CW print 136or 137.CW fprint 138at will. 139.Xx 140Support for electronic mail has been extended in many ways and now includes 141some new spam filtering tools, 142much better (and more standard) handling of MIME messages, 143the ability to render incoming HTML mail, 144and much more. 145.LP 146There are so many changes to the programming interfaces of the system 147that they are described in a separate document, entitled 148.I 149Changes to the Programming Environment in the Fourth Release of Plan 9. 150.R 151Please read it before you start updating your own software to run under the new system. 152.LP 153The installation method has also changed and we're moving towards a new 154method for maintaining updates. 155The Plan 9 Wiki 156.CW http://plan9.bell-labs.com/wiki/plan9 ) ( 157and Usenet group 158.CW comp.os.plan9 ) ( 159are the places to visit to learn more and stay current. 160In particular, the installation notes are now maintained in the Wiki; 161the traditional papers on installation and start-up are gone. 162.LP 163There's lots more new stuff. 164If you have problems, mail 165.CW 9trouble@plan9.bell-labs.com 166or, better, check the wiki 167.CW http://plan9.bell-labs.com/wiki/plan9 168or ask the Usenet newsgroup 169.CW comp.os.plan9 . 170.LP 171Good Luck! 172