Frank,
The error message means that the module ipmi_si could not find the IPMI hardware device to talk to.
In the case of success it works like this:
* you call modprobe ipmi_si
* kernel loads that module into memory
* kernel calls initialization routine within that module
* initialization routine finds hardware device and tells the kernel that all is well
* there is a song and dance involving udev to create the /dev/*ipmi* device nodes
* ipmitool uses those device nodes to talk to the hardware
In your case, this is what happened:
* you call modprobe ipmi_si
* kernel loads that module into memory
* kernel calls initialization routine within that module
* initialization routine does not find hardware device and tells the kernel that it failed
* kernel unloads the module again. It passes a very short error status back to you. This is where the "Error inserting ... no such device" message comes from. This is also why "lsmod" does not show the ipmi_si module.
* no /dev/*ipmi* device nodes were created
* ipmitool does not see the device nodes
If you look at dmesg, the module initialization routine might have printed a more specific error message there. If you find such an error message, chances are you can use google to fix your situation. (or maybe you just need a different ipmi module for your computer)
Hans