CONSOLEFS(4) CONSOLEFS(4)
NAME
consolefs, C - file system for console access
SYNOPSIS
aux/consolefs name dev [ name dev ... ]
C system
DESCRIPTION
To ease administration of multiple machines one might attach
many serial console lines to a single computer. Consolefs
is a file system that lets multiple users simultaneously
access these console lines. Each name/dev pair represents
the name of a console and the serial line device associated
with it. Consolefs presents a single level directory with
two files per console: name and namectl. Writes of name are
equivalent to writes of dev and reads and writes of namectl
are equivalent to reads and writes of devctl. Consolefs
broadcasts anything it reads from dev to all readers of
name. Therefore, many users can con(1) to a name, see all
console output, and enter commands to the console.
To keep users from inadvertently interfering with one
another, notification is broadcast to all readers whenever a
user opens or closes name. For example, if user boris opens
a console that users vlad and barney have already opened,
all will read the message:
[+boris, vlad, barney]
If vlad then closes, boris and barney will read:
[-vlad, boris, barney]
Consolefs posts the client end of its 9P channel in
/srv/consolefs; mount (see bind(1)) this file to see the
consoles. An example of 2 consoles complete with console
logging is:
% aux/consolefs bootes /dev/eia0 fornax /dev/eia1
% mount /srv/consoles /mnt/consoles
% ls -p /mnt/consoles
bootes
bootesctl
fornax
fornaxctl
% cat /mnt/consoles/fornax >> /sys/log/fornax &
% cat /mnt/consoles/bootes >> /sys/log/bootes &
The rc(1) script C automates this procedure. It uses
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CONSOLEFS(4) CONSOLEFS(4)
import(4) to connect to /mnt/consoles on the machine con-
nected to all the consoles, then uses con(1) to connect to
the console of the machine system. The script must be edited
at installation by the local administration to identify the
system that holds /mnt/consoles.
FILES
/srv/consoles Client end of pipe to server.
SOURCE
/sys/src/cmd/aux/consolefs.l
/rc/bin/C
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