[opensuse] Connecting to serial port (to be console) of 2nd suse box
01234567890123456789012345678901234567890123456789012345678901234567890123456789 I have 3 machines in this setup. The setup being: - Room "big closet" (where I sit) contains "mDesktop". - Room "small closet" contains machines "mTest" and "mControl". - Machines mControl and mTest have a serial "crossover" cable (null modem) connecting their /dev/ttyS0 (COM1) ports. - I am using 'ssh' from mDesktop to connect into mControl. - I've setup mTest to listen on it's serial port for a login with the line in its "/etc/inittab": S0:12345:respawn:/sbin/agetty -L 38400,19200,9600 ttyS0 linux I sent -HUP to init on mTest to signal rereading its inittab. mTest appears to be spawning "agetty" on ttyS0 as expected/desired. *** my problem(s): - How do I use mControl's ttyS0 port to connect to mTest? - What program do I use on mControl to connect me to mTest? Notes/thoughts: I remember doing this with 'cu' in the past, but I've never felt entirely comfortable with this due to a comment in the 'cu' manpage: BUGS "This program does not work very well" Is there a preferred alternative? I vaguely remember using some sort of 'call device' like 'cua0' in cu that corresponded to ttyS0 with an invocation like: cu -l /dev/cua0 I've tried the above and "cu -l /dev/ttyS0" and neither work: mDesktop > cu -l /dev/ttyS0 cu: open (/dev/ttyS0): No such device or address cu: /dev/ttyS0: Line in use mDesktop > cu -l /dev/cua0 cu: open (/dev/cua0): No such file or directory cu: /dev/cua0: Line in use ------ The different error messages, in some part, have to do with the fact that under the new udev-managed /dev directory "cua0" no longer exists. Don't even remember, offhand, what it's Major-Minor device numbers were, but don't think that would necessarily help since the numbers under udev are allocated differently. Also, there doesn't seem to be any "default" config files setup for uucp anymore (I think it had some commented-out line that, commented-in, enabled cua0, but it has been a while. Is there a better way to do this these days? I also need to know how to do this to be able to connect to local devices that provide a serial port for management (when managing them sans-network). Eventually, I'd like to be able to use the serial port as mTest's console (as it's not always convenient to find a 'head' to attach it to (esp. right now with the VGA-monitor in that room having died recently :-))... TIA... Linda -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
*** my problem(s): - How do I use mControl's ttyS0 port to connect to mTest? - What program do I use on mControl to connect me to mTest?
I have used 'minicom' in the past to do this sort of thing. Peter -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Wed, 2008-01-09 at 12:46 -0800, Linda Walsh wrote:
01234567890123456789012345678901234567890123456789012345678901234567890123456789 I have 3 machines in this setup. The setup being:
- Is there a preferred alternative? I vaguely remember using some sort of 'call device' like 'cua0' in cu that corresponded to ttyS0 with an invocation like: cu -l /dev/cua0 Linda, load the "lessons for Lizards" documentation, and look at
How-To Access COM Port (RS-232 client/server) This uses the "screen" command, and is really perfect for you to get a console over the serial port. Or minicom...or why not a network connection, and tie them together with a hub or switch? Tom in NM -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Peter Bloomfield suggested minicom (thanks) and Tom Patton wrote:
On Wed, 2008-01-09 at 12:46 -0800, Linda Walsh wrote:
I have 3 machines in this setup. The setup being: --- Linda, load the "lessons for Lizards" documentation, and look at How-To Access COM Port (RS-232 client/server)
??lessons for Lizards" documentation? *blink* Say wah? What's a "lessons for Lizards?"...wait...suse? Lizard? still unclear...what or which document are you talking about? (sorry)
This uses the "screen" command, and is really perfect for you to get a console over the serial port. Or minicom.
ahh...screen or minicom I can probably find documentation on...but the lessons for lizard thing's got me stumped. :-)
..or why not a network connection, and tie them together with a hub or switch?
They are tied together with a gigabit switch...but when the kernel first boots, the network isn't available until later. I need to use the serial port (AFAIK), if I want access to the console. Have you ever done that over the network?...where you see all the bootup messages come over the serial line and then it leaves you at the login prompt on /dev/console (but over a serial port). Two reasons 1) monitor that was shared by these machines died (being replaced, but that doesn't help in the short term). 2) I want remote access to the console startup messages so I can monitor a boot to see if it goes ok and if not, what died. The computers I want to use the serial port for are in another room from where I'm sitting -- even when they had a working monitor, it was only for monitoring bootups or doing machine maintenance (the systems I want to access the serial port console on don't even run a desktop). Thanks.. Linda -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Thu, 10 Jan 2008 17:22:56 -0800, Linda Walsh <suse@tlinx.org> wrote:
Peter Bloomfield suggested minicom (thanks) and Tom Patton wrote:
On Wed, 2008-01-09 at 12:46 -0800, Linda Walsh wrote:
I have 3 machines in this setup. The setup being: --- Linda, load the "lessons for Lizards" documentation, and look at How-To Access COM Port (RS-232 client/server)
??lessons for Lizards" documentation? *blink* Say wah? What's a "lessons for Lizards?"...wait...suse? Lizard? still unclear...what or which document are you talking about? (sorry)
Google *is* your friend. Search for it. "lessons for lizards openSUSE" gives many hits with the best right at the top. -- Patrick Shanahan Plainfield, Indiana, USA HOG # US1244711 http://wahoo.no-ip.org Photo Album: http://wahoo.no-ip.org/gallery2 Registered Linux User #207535 @ http://counter.li.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Linda Walsh wrote:
Is there a preferred alternative? I vaguely remember using some sort of 'call device' like 'cua0' in cu that corresponded to ttyS0 with an invocation like: cu -l /dev/cua0
I've tried the above and "cu -l /dev/ttyS0" and neither work
It really helps if you do a 'modprobe 8250' before hand (not that this is crystal clear, BTW). For some reason, I thought when my hardware was probed, it would find and load drivers corresponding to my hardware. I guess that's not entirely true? Anyway, loading the standard serial port drivers made 'cu' "magically" start working: cu -l ttyS0 -s 38400 was/is all that was needed. I looked over screen and minicom. Guess I should have been more specific -- I wanted a command-line tty interface. Screen & minicom are both curses based and take over the window they are in. Using cu and specifying the line as above requires no configuration or setup (just loading the dang drivers!) :-) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
participants (4)
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Linda Walsh
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Patrick Shanahan
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Peter Bloomfield
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Tom Patton