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bad behavior of KVM console's touch pad

Samer Dahr

bad behavior of KVM console's touch pad

I have 4 servers HP proliant DL380G5 on which i have installed linux red hat 4. the servers are managed via a unique console related to a KVM switch.
when I have installed the KVM for the first time, the mouse (touch pad ) of the console did not work at all, then , i have disconnected the KVM switch and I have attached the console directly to one of the servers, and so, the mouse is working very well.
when i have reconnected the KVM switch back , the mouse moved , so it is working now, but its behavior is very strange, and very bad, i dont know how to explain it, but it is moving down when trying to move left for exemple, it makes right clicks without doing it myself...

Could anyone help me resolving this issue?

Thanks a lot and Best regards
Steven E. Protter
Exalted Contributor

Re: bad behavior of KVM console's touch pad


Try connecting if possible a normal mouse to the KVM.

Its pretty common that Linux won't use certain mouse types via KVM. Laser mice don't work via KVM, but regular ball mice do.

Eventually the OS will catch up.

Steven E Protter
Owner of ISN Corporation
Honored Contributor

Re: bad behavior of KVM console's touch pad

The protocol between the touchpad and the server has got out of sync, probably because the KVM switch cuts the power to the mouse when switching it from one server to another.

With Linux, you can usually recover from this fairly easily. If you're using the X Window System GUI, press Ctrl-Alt-F1 to switch to text-mode virtual console. Move the mouse, then press Ctrl-Alt-F7 to switch back to the GUI.

If you are not using the GUI or the procedure above won't help, restart the "gpm" process. Switch to text mode first if necessary (as above).

sh /etc/init.d/gpm restart

With most Microsoft OSs, the only way to recover from this state is to reboot the server! (as far as I know :-)

With newer kernels, there are some parameters that might help, but I'm not sure whether they're implemented in Linux kernel 2.6.9 (RHEL 4's kernel version) or not.

As RHEL 4 has the psmouse driver compiled in the kernel and not as a separate module, the parameters must be specified as kernel boot parameters:

Makes the mouse driver to automatically reset the mouse after receiving 2 "bad" packets from the mouse.


Forces the mouse to be reset after the mouse has been idle for 120 seconds.