[NTLUG:Discuss] console on headless server... no serial port

[David Simmons]

Trick I know to do needs two servers.....the console of one is the
input for another (and vice-versa)....that way you can watch bios/boot
from the one while rebooting the other.  There's fancy card that'll do
that same thing...I'll have to google it.

-dave

On Thu, Jan 7, 2010 at 12:31 PM, Chris Cox <cjcox at acm.org> wrote:
>
> On Thu, 2010-01-07 at 12:04 -0600, Eric Waguespack wrote:
> > I have a small form factor server that I run headless, but I would
> > like to be able to console into it during boot, it only has usb ports,
> > is it possible (with usb / serial adapters) to console in via usb?
> >
>
> yes.
>
> It can be a chicken and egg thing though.
>
> For example, if you want to do this AND reach the BIOS settting, then
> the BIOS would have to support (for example) a serial terminal connect
> via USB (again, just an example).  But this probably isn't what you
> are wanting (plus it's probably not possible on your host without
> adding some special hardware).
>
> With regards to most things, if your initrd is loading the USB
> modules, or it's built into your kernel (not a module) and you have
> a proper USB to Serial adapter (again, I'm assuming one kind
> of popular headless console) and that module is also built in or inside
> of the initrd, then you should be able to pass console= on the boot
> line to specify where the console resides.
>
> One problem... USB is "dynamic" so the device name can float depending
> on what is connected.  I'll assume you only have one USB to serial
> device though...
>
> I haven't actually tried what I'm describing above. Most of my headless
> boxes have a serial port.
>
> With regards to the "console=" parameters, you can read all about that
> in the kernel-parameters.txt file and serial-console.txt files in the
> kernel documentation for your distro.
>
> You'll have to edit your /etc/inittab (or wherever things get started
> from) and add something to run a respawning "getty" on the USB serial
> line (e.g. I use agetty).
>
> (below is an example for a serial situation, and not a USB serial)
> S0:12345:respawn:/sbin/agetty -L 115200 ttyS0 vt102
>
> Supposedly grub can do serial console support.  I have not had to try
> this because usually my systems have a BIOS based serial redirect that
> will work clear up until the Linux kernel takes over (so I get to do
> system BIOS clear through grub using that).
>
> Anyway, things to look at (no guarantees on making this work).
>
> There "might" be other options for a "console", but I'm not aware
> of anything off the top of my head.  There are certainly hints of
> functionality to be found in things like "linuxrc" (SUSE) where
> they allow for headless installation over ssh, vnc, etc.  So...
> other things might be possible (just so many issues in making
> something like this work).
>
>
>
>
> _______________________________________________
> http://www.ntlug.org/mailman/listinfo/discuss



--
Those with sight believe what's believable. Those with vision know
what's unbelievable.