ConMan FAQ ------------------------------------------------------------------------------- Q: I'm running ConMan on a large cluster and it crashes every time at startup. How do I configure it to handle more than 1024 consoles? A: ConMan versions < 0.1.9 are based on select() and are thereby limited by the number of file descriptors. A file descriptor is needed for each console, and another is needed for each log file. If you are logging each console, these versions will be unable to open more than ~510 consoles. Under Linux, versions >= 0.1.8.3 can sidestep this limitation if they are compiled against an increased __FD_SETSIZE in the /usr/include headers. Versions >= 0.1.9 are based on poll() and are no longer constrained by the number of file descriptors. The daemon sets the current RLIMIT_NOFILE (ie, the limit on the number of open file descriptors) to the maximum allowable "hard" limit. On Linux, the system nofile hard limit can be set in /etc/security/limits.conf. ------------------------------------------------------------------------------- Q: I have a cluster where each node's serial port is the console for the next node. I would like to be able to access all consoles from a single host. Is there a "serial port forwarding" mechanism to forward the local serial port to a single conmand daemon? A: ConMan does not currently support forwarding consoles from one daemon to another. However, several serial port forwarders exist: http://freshmeat.net/projects/sredird/ http://freshmeat.net/projects/sercd/ http://freshmeat.net/projects/ser2net/ http://freshmeat.net/projects/msredird/ Chris Worley reports success with ser2net: > Date: Tue, 02 May 2006 11:12:09 -0700 > From: "Worley, Chris B" <chris.b.worley@intel.com> > Subject: RE: Conman via distributed serial ports > > Ser2net works great. > > I setup my "/etc/ser2net.conf" file on each node with: > > 2299:telnet:100000:/dev/modem:57600,NONE,1STOPBIT,8DATABITS,-RTSCTS,-XONXOFF > > And my /etc/conman.conf as: > > CONSOLE name="n1" dev="/dev/ttyUSB0" log="n1" > CONSOLE name="n2" dev="n1:2299" log="n2" > CONSOLE name="n3" dev="n2:2299" log="n3" > CONSOLE name="n4" dev="n3:2299" log="n4" > CONSOLE name="n5" dev="n4:2299" log="n5" > CONSOLE name="n6" dev="n5:2299" log="n6" > CONSOLE name="n7" dev="n6:2299" log="n7" > CONSOLE name="n8" dev="n7:2299" log="n8" > > And run ser2conf on each node from inittab with: > > ser2net -n -p 2298 -------------------------------------------------------------------------------