monitoring serial consoles (was Re: erorrs from spec_getpages)

[Dmitry Morozovsky]

On Sat, 18 Oct 2003, Dan Langille wrote:

DL> Moving this thread over to -questions, please don't include
DL> freebsd-stable at freebsd.org in the reply

agrred [but the please don't drop me from CC list, as I do not read
-question ;)]

DL> > That's why I always try to set up logged serial console for any machine with
DL> > more than marginal importance. BTW, comms/conserver-com port is of great use
DL> > for this purpose!
DL>
DL> I have an 8 port serial Boca card here, which I have yet to get
DL> running.  How does comms/conserver-com work?  I couldn't determine
DL> that from the FAQ.  Does it need any hardware?  How does it monitor
DL> the serial console?  Do you connect two boxes together via their
DL> serial ports?  Box A reports on Box B, and vice versa?
DL>
DL> Or does it just monitor the serial console and report back to a
DL> central server?

For two machines each capable of 2 serial ports (usually, but it's not that
obvious with modern mobos and/or server/19"/compact platforms), I'd connect
each sio0/com1 to other's sio1/com2 with null-modem cable, enable serial
console and getty at ttyd0.

For servers cluster, one of machines should be elected as comserver and
equipped with pultiport card, other's sio0's connected to its multiport, and
its own sio0 -- to sio1 somewhere.

each machine with remote console target then runs comserver. In the simplest
case of thw machines each conserver.cf would be like

-- 8< --
# name:path:baud:logfile:mark:break
LOGDIR=/var/log
com1:/dev/cuaa0:9600p:&:30ma
#
%%
# Access part
#
trusted: localhost host.domain.tld
#allow: localhost woozle.rinet.ru host.domain.tld
refuse: 0.0.0.0/0
-- 8< --

conservers could also be cascaded, but that's another beast story ;-)

DL> > I assumed here that usually you have more than one machine per physical
DL> > location; otherwise, I'd set up remote logging, preferrably to two different
DL> > machines via two different interfaces, but such ideal network design is
DL> > *rarely* reqchable ;-)
DL>
DL> I have one location which has only one box.  That box and the
DL> bandwidth is kindly donated by BCHosting.com, and hosts
DL> freebsddiary.org, freshports.org, etc.  It does about 45GB a month
DL> (at last check).  I'd like to have a serial console there.  But if it
DL> could the console remotely, that would be good.

well, there are devices which do real _remote_ console job; I suppose you can
politely ask BCHosting if they can setup such remote console for you; it can
greatly simplify remote upgrades, for example. However, not any (read: rare)
non-rackmount mobo is able to redirect, say, BIOS output to com port, so that
you can't remotely tweak ACPI and/or memory timings...

Good colocation support is almost always great; if you have good hardware
support _in_addition_ to that, you can sleep much better ;-P

Sincerely,
D.Marck                                     [DM5020, MCK-RIPE, DM3-RIPN]
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*** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck at rinet.ru ***
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