Re: FW: udev documentation

[Greg KH <greg@kroah.com>]

On Thu, Jul 15, 2010 at 03:53:11PM +0000, Donnelly, John (ISS (SNI), Houston) wrote:
>  
> >> There are 60-net.rules under /etc/udev ... Are ethernet devices a separate category ?
> 
> >No.
> 
> >What are you looking to have udev do?  What is the problem you are having?
> 
> Using static MAC's within a system creates config conflicts when
> adapters are exchanged that have different PCI-ID and drivers. Often
> the reconfigured machine will not boot (because of  modprobe entries )
> or network (ifcfg-ethX ) bring up fails because of stale configuration
> data left behind by the s-c-n tools. 

Then don't do that :)

Wait, what is "s-c-n" tools?

> I am seeking to understand how make a more dynamic ETHERNET
> configuration manager (and underlying components) that bonds PCI-IDs
> and drivers to a ETHERNET device better than they currently do.

The in-kernel driver does this type of "bonding".  You mean you want to
change your ethernet device naming to be more flexible, right?

> When I remove/replace an adapter with a different one I want to invoke
> udev to clean up stale ethX and modprobe references.

What do you mean by "modprobe references"?  The kernel will auto-load
drivers when it finds a device that it needs a driver for, right?

And when you remove an ethernet device, the kernel removes the ethX
device, and any userspace mappings you had you need to then clean up as
well on your own.

> For instance .. how does /etc/udev/rules.d/60-net.rules get invoked ?

When a ethX device is reported as created by the kernel.

> My impression now is a driver of the "net" class has to post a message
> to udev to get processed by udevd, which rules a script/program.

Yes, but the core kernel logic does the "message send" here, and udevd
handles it automatically.

hope this helps,

greg k-h