KVM Switch bug

KVM Switch bug

[Stijn Verrept]

Hi,

When switching using a KVM switch I loose keyboard (only in Linux so it's not 
hardware related)

I'm using a ADDERView KVM switch (used to connect multiple PC's to one key / 
mouse / screen).  After looking on the internet I have found lots of other 
users having the same problem, with other KVM switches.
This happens both in console as in X.  Keyboard and mouse I use are both PS/2.

Using Linux version: 2.4.18-6mdk (gcc version 2.96 20000731)

I think anything else is pretty irrelavant.

Kind regards,

Stijn Verrept.

BTW Can I get any feedback on this?

RE: KVM Switch bug

[Alok K. Dhir]

This is most likely a function of your KVM switch.  I used to use a
Logitech two way KVM which worked fine switching back and forth, except
Linux never saw the mouse wheel, and occassionally I'd lose keyboard
(both in Windows and Linux) which typically required unplugging and
replugging the keyboard.  The Logitech also had the insanely stupid
design of using the ctrl key for switching.  Finally, it adversely
affected my key repeat rate (which drove me crazy).

I now use a Linkskey KVM-K104M ($64.00 at newegg.com) - a four way which
costs less than the 2-way logitech, in which everything works without a
hitch, including the mouse wheel, in both Windows and Linux.  EXCEPT -
in Linux, the wheel doesn't work after I switch away from it and back.
Resetting the X display by switching to a console terminal (ALT-CTRL-Fn)
and back fixes it however.  It also uses a much more sensible key for
switching (double click scroll lock followed by a number (1-4)).  AND -
as a bonus, my key repeat is back up to my desired rate.

I've heard of people having all kinds of problems - the problems are
almost always a function what KVM they're using.

I cannot recommend the Linkskey highly enough.

Alok

> -----Original Message-----
> From: linux-kernel-owner@vger.kernel.org 
> [mailto:linux-kernel-owner@vger.kernel.org] On Behalf Of Stijn Verrept
> Sent: Thursday, April 11, 2002 2:51 PM
> To: linux-kernel@vger.kernel.org
> Subject: KVM Switch bug
> 
> 
> Hi,
> 
> When switching using a KVM switch I loose keyboard (only in 
> Linux so it's not 
> hardware related)
> 
> I'm using a ADDERView KVM switch (used to connect multiple 
> PC's to one key / 
> mouse / screen).  After looking on the internet I have found 
> lots of other 
> users having the same problem, with other KVM switches.
> This happens both in console as in X.  Keyboard and mouse I 
> use are both PS/2.
> 
> Using Linux version: 2.4.18-6mdk (gcc version 2.96 20000731)
> 
> I think anything else is pretty irrelavant.
> 
> Kind regards,
> 
> Stijn Verrept.
> 
> BTW Can I get any feedback on this?
> -
> To unsubscribe from this list: send the line "unsubscribe 
> linux-kernel" in the body of a message to 
> majordomo@vger.kernel.org More majordomo info at  
http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Re: KVM Switch bug

[Mr. James W. Laferriere]

	Hello Stijn ,  Using a belkin here .  So far no problems .  But if
	I do things with power on/off at same time swap console I can get
	the KVM confused .  But I have to really try to do so .
		Hth ,  JimL

On Thu, 11 Apr 2002, Stijn Verrept wrote:
> Hi,
> When switching using a KVM switch I loose keyboard (only in Linux so it's not
> hardware related)
> I'm using a ADDERView KVM switch (used to connect multiple PC's to one key /
> mouse / screen).  After looking on the internet I have found lots of other
> users having the same problem, with other KVM switches.
> This happens both in console as in X.  Keyboard and mouse I use are both PS/2.
> Using Linux version: 2.4.18-6mdk (gcc version 2.96 20000731)
> I think anything else is pretty irrelavant.
> Kind regards,
> Stijn Verrept.
> BTW Can I get any feedback on this?

       +------------------------------------------------------------------+
       | James   W.   Laferriere | System    Techniques | Give me VMS     |
       | Network        Engineer |     P.O. Box 854     |  Give me Linux  |
       | babydr@baby-dragons.com | Coudersport PA 16915 |   only  on  AXP |
       +------------------------------------------------------------------+

Re: KVM Switch bug

[Roach]

	I have both a dell kvm and a belkin kvm switch and they work fine with the 
dell kvm requiring me to hit the print screen again to get the keyboard to 
work some times. 


On Thursday 11 April 2002 04:27 pm, Mr. James W. Laferriere wrote:
> Hello Stijn ,  Using a belkin here .  So far no problems .  But if
> 	I do things with power on/off at same time swap console I can get
> 	the KVM confused .  But I have to really try to do so .
> 		Hth ,  JimL
>
> On Thu, 11 Apr 2002, Stijn Verrept wrote:
> > Hi,
> > When switching using a KVM switch I loose keyboard (only in Linux so it's
> > not hardware related)
> > I'm using a ADDERView KVM switch (used to connect multiple PC's to one
> > key / mouse / screen).  After looking on the internet I have found lots
> > of other users having the same problem, with other KVM switches.
> > This happens both in console as in X.  Keyboard and mouse I use are both
> > PS/2. Using Linux version: 2.4.18-6mdk (gcc version 2.96 20000731)
> > I think anything else is pretty irrelavant.
> > Kind regards,
> > Stijn Verrept.
> > BTW Can I get any feedback on this?
>
>        +------------------------------------------------------------------+
>
>        | James   W.   Laferriere | System    Techniques | Give me VMS     |
>        | Network        Engineer |     P.O. Box 854     |  Give me Linux  |
>        | babydr@baby-dragons.com | Coudersport PA 16915 |   only  on  AXP |
>
>        +------------------------------------------------------------------+
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

Re: KVM Switch bug

[Keith Owens]

On Thu, 11 Apr 2002 20:50:36 +0200, 
Stijn Verrept <sverrept@vub.ac.be> wrote:
>When switching using a KVM switch I loose keyboard (only in Linux so it's not 
>hardware related)

For flakey KVMs, I define a user (switched) in /etc/passwd with the
same uid/gid as root and no password.  Instead of a normal shell, its
login entry is /usr/local/bin/switched which contains

#!/bin/sh
/etc/rc.d/init.d/gpm restart
/sbin/kbdrate -r 30

If there are any problems I log in as user switched, either keyboard or
network.  The script runs to reset mouse and keyboard then the user
exits.  The lack of password means that anybody can reset the KVM
devices to fix problems.