3 consolefs, C, clog \- file system for console access
21 To ease administration of multiple machines one might attach
22 many serial console lines to a single computer.
24 is a file system that lets multiple users simultaneously access
26 The consoles and permissions to access them are defined in the
30 .BR /lib/ndb/consoledb ).
33 is the same as that of other
37 Consoles are defined by entries of the form:
40 console=dirty dev=/dev/eia205
49 pair represents the name of a console and the device
52 presents a single level directory with up to three files
60 are equivalent to writes of
62 and reads and writes of
66 are equivalent to reads and writes of
74 will not exist if the underlying
76 does not provide them.
78 broadcasts anything it reads from
82 Therefore, many users can
86 see all output, and enter commands.
90 attribute causes newlines typed by the user to be sent to
91 the console as returns.
94 attribute/value pair specifies a bit rate for the
95 console. The default is 9600 baud.
98 attribute causes the console device
100 to be opened only when the corresponding
104 Access to the console is controlled by the
108 attributes/value pairs.
109 The uid values are user account names.
110 The gid values are the names of groups defined in
112 by entries of the form:
122 Groups are used to avoid excessive typing. Using
124 is equivalent to including a
131 To keep users from inadvertently interfering with one another,
132 notification is broadcast to all readers whenever a user
137 opens a console that users
141 have already opened, all will read the message:
144 [+boris, vlad, barney]
156 [-vlad, boris, barney]
160 posts the client end of its 9P channel in
162 and mounts this locally in
170 this file to see the consoles.
176 automates this procedure.
181 on the machine connected to all the consoles, then uses
183 to connect to the console of the machine
185 The script must be edited at installation
186 by the local administration to identify the
193 and writes every line read from it, prefixed
194 by the ASCII time to the file
197 An example of 2 consoles complete with console logging is:
200 % cat /lib/ndb/consoledb
203 console=bootes dev=/dev/eia0 gid=sys
204 console=fornax dev=/dev/eia1 gid=sys
206 % ls -p /mnt/consoles
211 % clog /mnt/consoles/fornax /sys/log/fornax &
212 % clog /mnt/consoles/bootes /sys/log/bootes &
215 The console server's default name space must
216 mount the consoles for
219 This can be arranged by adding
222 mount /srv/consoles /mnt/consoles
226 .BR /lib/namespace.$sysname .
228 .TF /lib/ndb/consoledb
231 Client end of pipe to server.
236 .B /lib/ndb/consoledb
237 Default user database.
239 .B /sys/src/cmd/aux/consolefs.c
243 .B /sys/src/cmd/aux/clog.c
246 Changing the gid's or uid's while
251 However, to add new consoles