What if I yank the PS/2 keyboard of my OpenBSD box?

What if I yank the PS/2 keyboard of my OpenBSD box?

Post by Robert K » Wed, 23 Oct 2002 13:17:29



Will the system hang?

Will I be able to plug it back in later without rebooting?

I could just try it without asking here first, but THAT wouldn't be any fun.

Not to mention I'd rather not kill uptime for so frivolous an experiment.

Thanks...

All the best,
Robert K S

 
 
 

What if I yank the PS/2 keyboard of my OpenBSD box?

Post by Timothy J. L » Wed, 23 Oct 2002 13:26:29




Quote:>Will the system hang?

>Will I be able to plug it back in later without rebooting?

Is this a PC?

If it is a PC, the BIOS needs to be set so that the "Halt on"
setting is on "No error" (or some other setting that excludes
halting on keyboard errors) if you want to be able to unplug
the keyboard without making it hang.  The default is usually
to halt on any error, which causes the system to hang if the
keyboard is unplugged.

--
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Timothy J. Lee
Unsolicited bulk or commercial email is not welcome.
No warranty of any kind is provided with this message.

 
 
 

What if I yank the PS/2 keyboard of my OpenBSD box?

Post by M Khom » Wed, 23 Oct 2002 14:03:52





>>Will the system hang?

>>Will I be able to plug it back in later without rebooting?

> Is this a PC?

> If it is a PC, the BIOS needs to be set so that the "Halt on"
> setting is on "No error" (or some other setting that excludes
> halting on keyboard errors) if you want to be able to unplug
> the keyboard without making it hang.  The default is usually
> to halt on any error, which causes the system to hang if the
> keyboard is unplugged.

BIOS notwithstanding my experience is that OpenBSD continues running (At
least since ver 2.2 when I first did it). I happen to have not enough
heads/hands and I rotate these on running systems (bodies). Later sparcs
will not reboot without keyboard present, but they do keep running on kb
disconnect. Must be all that power circuitry that the kb controls, and I
have managed to panic one (SS20) with one keyboard yank too many, so
plunge in at your level of risk-taking.

I relinquished my value of uptime years ago to the power grid (ComEd).
But I've had some headless and handless i386's that have gone through
many power cycles unassisted, although I do not know what m/board or
bios settings guarantee automatic reboot on power interrupt, while more
recent other i386's (ATX) just wait for human attention after an
interrupt :(.

In general reconnection of keyboard on running system restores console
I/O without reboot/panic. (a superstition I've developed is to yank/put
in one firm motion)

MK

 
 
 

What if I yank the PS/2 keyboard of my OpenBSD box?

Post by tedu » Wed, 23 Oct 2002 15:48:57



> >Will the system hang?

no.

Quote:> >Will I be able to plug it back in later without rebooting?

that worked for me using AT style, but not ps2 style.

Quote:> If it is a PC, the BIOS needs to be set so that the "Halt on"
> setting is on "No error" (or some other setting that excludes
> halting on keyboard errors) if you want to be able to unplug
> the keyboard without making it hang.  The default is usually
> to halt on any error, which causes the system to hang if the
> keyboard is unplugged.

unplugged during bootup you mean.  the act of unplugging the keyboard will
not cause the machine to halt if it is running.

--
Mediocrity is a sin.

 
 
 

What if I yank the PS/2 keyboard of my OpenBSD box?

Post by Timothy J. L » Thu, 24 Oct 2002 01:18:36



Quote:>But I've had some headless and handless i386's that have gone through
>many power cycles unassisted, although I do not know what m/board or
>bios settings guarantee automatic reboot on power interrupt, while more
>recent other i386's (ATX) just wait for human attention after an
>interrupt :(.

Old AT PCs will come back on when power is restored.  Newer ATX PCs
typically default to staying turned off (probably optimal for most
desktop use).  On some ATX PC motherboards, you can change the BIOS
setting for "AC Power Loss Restart" so that it turns on.  Not all
ATX PC motherboards have this feature, though (Asus boards that I've
seen generally do have it).  Be careful; I've seen some computers
marketed as servers that did not have this feature, and needed someone
to press the button after a power loss.

If you are looking for an ATX PC motherboard or computer for server
room use, be sure to check for this feature.

--
------------------------------------------------------------------------
Timothy J. Lee
Unsolicited bulk or commercial email is not welcome.
No warranty of any kind is provided with this message.

 
 
 

What if I yank the PS/2 keyboard of my OpenBSD box?

Post by M Khom » Thu, 24 Oct 2002 05:17:49



> Old AT PCs will come back on when power is restored.  Newer ATX PCs
> typically default to staying turned off (probably optimal for most
> desktop use).  On some ATX PC motherboards, you can change the BIOS
> setting for "AC Power Loss Restart" so that it turns on.  Not all
> ATX PC motherboards have this feature, though (Asus boards that I've
> seen generally do have it).  Be careful; I've seen some computers
> marketed as servers that did not have this feature, and needed someone
> to press the button after a power loss.

> If you are looking for an ATX PC motherboard or computer for server
> room use, be sure to check for this feature.

Agreed! Cannot be overemphasized. Although OBSD will run on any ole
i386, there's a (large) class of m/boards that are not suitable for 'max
uptime' deployment!!