[ale] Serial consoles

[tlewis at mindspring.com (Todd Graham Lewis)]

On Sat, 18 Jan 1997, Byron A Jeff wrote:

> Now that's interesting. Exactly how does that happen? Each machine has
> a modem and phone line? Dialing up on the phone line reboots the machine and
> connects the modem to the serial line? Like I said interesting...

Well, you can use these things called "portmasters", or "multi-port serial
cards", to allow you to access a number of machines from _another_
machine, all right over the network.  If you run a multi-port serial card
on an old 386, then you can have encrypted, etc. access to your machines
at the boot prompt, allowing you to switch kernels remotely, see where the
machine is hanging on reboot, etc.

> Tell me more. I do have a couple of machines that I'd like to be able to
> boot remotely. However there are no phone lines available to signal the
> reboot.

You can signal the reboot with "ssh -l root machine \"shutdown -r now\"".

Without serial consoles, you just have to pray that they do come back up
properly, which many times, especially in the face of abnormal failure in
the first place, is not the case.

__
Todd Graham Lewis             Linux!                 Core Engineering
Mindspring Enterprises  tlewis at mindspring.com   (800) 719 4664, x2804