After playing with con:port, and its use in a chroot, I wonder if those with versions of UML documentation which refer to con:port would find the following two pieces of information useful: ---
*** Avoiding the hang during boot for telnet :port consoles *** Some sites suggest that :port will work well so long as the console in question is not the "main console". Other sites suggest that "If you attach the main console to a portal, then the UML boot will appear to hang. In reality, it's waiting for a telnet to connect, at which point the boot will proceed." It turns out that this deserves more explanation. One example to making use of :port could be something like: con=none con0=null,fd:1 con1=fd:0,fd:2 con2=port:5000 In this example we use normal stdin/stdout/stderr to give us output from con0, and direct console access on con1 from the current session. console2 is only accessible using telnet localhost 5000 A suitable /etc/inittab for this could be: 1:2345:respawn:/sbin/mingetty tty1 2:2345:respawn:/sbin/mingetty tty2 #3:2345:respawn:/sbin/mingetty tty3 #4:2345:respawn:/sbin/mingetty tty4 #5:2345:respawn:/sbin/mingetty tty5 #6:2345:respawn:/sbin/mingetty tty6 This example would possibly hang until the telnet command was executed. It seems that UML blocks if the telnet has not connected AND there is an attempt to write to that console. For tty1 a write is hard to avoid during boot (so dont use :port for tty1/console1), but for tty2 and beyond the solution is simple... avoid the write. In Fedora 2, tty2 and beyond are only written to in one place, from within the /etc/rc.sysinit file. Do something like: grep inittab /etc/rc.sysinit This produces for i in `LC_ALL=C grep '^[0-9].*respawn:/sbin/mingetty' /etc/inittab | sed 's/^.* tty\([0-9][0-9]*\).*/\1/g'`; do Now, just replace [0-9] with [0-1] and you are finished. No more hangs. Note that Fedora 7 does not seem to have this line, and so the hang should not happen long as tty1 is not a telnet-based :port console. *** Using this in a chroot *** A chroot UML which uses :port seems to need the following to be available in the chroot $JAIL/usr/sbin/in.telnetd $JAIL/usr/lib/uml/port-helper mknod $JAIL/dev/ptmx c 5 2 mkdir $JAIL/dev/pts mount --bind /dev/pts $JAIL/dev/pts If in.telnetd and port-helper are dynamically compiled, you need their libraries to (you can use ldd to find this out). For me, this was mkdir $JAIL/lib cp -p /lib/libutil.so.1 $JAIL/lib cp -p /lib/libc.so.6 $JAIL/lib cp -p /lib/ld-linux.so.2 $JAIL/lib Your UML process does not need to be root for this to work. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
