[nSLUG] linux home or workplace automation and Universal Powerline Bus

Daniel Morrison draker at gmail.com
Sun Sep 21 22:54:58 ADT 2008

2008/9/21 George N. White III <gnwiii at gmail.com>:

> I wonder if the unwanted changes are coming from udev/hal and networkmanager
> (which I don't intentionally use on the systems in question, but could have
> crept in via some update as they seem to be the default these days)

You've got a pretty big setup there, and I think my ideas are run out for
now.  A few things to reply to:

> The SGI's still have "ethernet cable disconnected" messages, but it
> gets "connected" after a few seconds and the duplex settings are still
> good.  There have been a few times when the system lost the default
> route, so wouldn't talk to anything that wan't on the same subnet.

Strange - that sounds like software doing ifconfig up/ifconfig down.

> I suppose I should check the linux drivers and try setting options when
> the module is loaded,  If that fails, I can think about building custom
> kernels.  I see only a few options for e100, but for e1000:

> $ modinfo e1000
> [...]
> description:    Intel(R) PRO/1000 Network Driver
> [...]
> parm:           KumeranLockLoss:Enable Kumeran lock loss workaround

> What is a Kumeran lock?

My google research suggests it's for the ICH8 chipset, which has an
integrated e1000.  On this chipset there is some "lock loss"
issue, for which there is a workaround.  With this option you can disable
the work around -- presumably if you're not using an ICH8.

But draw your own conclusions:


>> Definitely I would be very concerned about your '800 desktops rebooting at
>> once' issue.  If there's anyway you could arrange staggered boots, either
>> by staggering the power, or maybe... each system does a 'sleep
>> <myroomnumber>/100' early in the boot sequence!

> I'll suggest that.

It occurs to me that _dividing_ by 100 throws away lots of low order bits
in the room number; taking the modulus of the room number into 100 might
be better.  Or, it might result in 'columns' of systems in your building
booting all at once, instead of 'floors'! :)

Best of luck,


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