[GTALUG] war story: keyboard failure leads to sustained mayhem
D. Hugh Redelmeier
hugh at mimosa.com
Mon Jul 6 14:37:40 UTC 2015
| From: James Knott <james.knott at rogers.com>
| On 07/06/2015 09:10 AM, Kevin Cozens wrote:
| > On 15-07-05 10:59 PM, D. Hugh Redelmeier wrote:
| >> - apparently I really only use the KVM for booting; it would be
| >> nice if PCs had been designed to be happy headless
| >
| > In older days (a few generations of PC ago) there used to be a BIOS
| > setting where you could tell it to ignore keyboard errors.
| I have 4 computers here, one with a year old motherboard. 3 of them can
| run headless and the other, an old Compaq, I just leave an old keyboard
| plugged in, but still access it via KVM.
Before I got a PC, I had Sun workstations. They were willing to talk
via a serial port to a "console" (they could use a display and
keyboard too). This let you do things like reboot when hung, watch
all the exciting messages during booting, configure the machine, run
hardware diagnostics, etc.
I don't really want to lose those functions. On PCs, they seem to
require a console (or some quite expensive "management" features).
That's why I use a KVM (and grumble).
I think that the expensive management functions use ethernet
transport. For security, it ought to be separate from other networks.
I have no experience with them. Unfortuately, I think that the
protocols are proprietary and different for each brand of computer.
KVMs are either expensive or deficient. Or both.
- cheap ones only support VGA, a very obsolete standard
- some cheap KVMs don't pass DDC info so the OS cannot determine
characteristics of the monitor. This causes a variety of problems
(some modern Linux distros won't work out of the box with this).
- some better cheap KVMs pass DDC information, but only to the
computer currently selected. This works badly after a power failure
when each computer is rebooting at the same time.
- there are issues (that I don't understand) about keyboard and mouse
states carrying over on switching.
- I have another KVM that is normally sold for ~$500 that does a lot
right: support dual-link DVI, does pass DDC to all computers. I
paid $100, so that was a great choice. Even so, it gets a bit
confused by some mice.
HDMI switches are quite cheap these days. That would handle the V
part of KVM. Maybe the clutter of multiple keyboards and mice would
be OK. HDMI includes an ethernet signal now. Someone should build a
pair of dongles to ship K and M stuff over that channel. USB over
ethernet is probably already a thing.
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