[systemd-devel] Proposal: integrate biosdevname into systemd tree

[Koen Kooi]

Op 4 jan. 2013, om 10:54 heeft Reindl Harald <h.reindl at thelounge.net> het volgende geschreven:

> 
> 
> Am 04.01.2013 10:40, schrieb Alexander E. Patrakov:
>> 2013/1/4 Reindl Harald <h.reindl at thelounge.net>:
>>> but hopefully /etc/udev/rules.d/70-persistent-net.rules will be recognized
>>> forever if it exists because there are many servers especially virtual
>>> ones where you hardly need to control ethernet device names to avoid
>>> breaking iptables-scripts as example
>> 
>> Yes, the existing rules will continue to be recognized. The bug is
>> that even they are intrinsically unreliable (as happened with that
>> rented server), so I think you actually don't want that.
> 
> how can something like this be unreliable?
> hwaddresses does not change randomly

Actually, they do for a lot of 'embedded' setups. If you have an SMSC usb-ethernet chip with a blank eeprom (e.g. a beagleboard xM) the kernel will assign a random mac on 1) every reboot (3.x kernels) or 2) every ifup (2.6.x kernels). If you have a board where the bootloader is supposed to read an eeprom or hidden register and pass it to the kernel this will fail if you use a devicetree enabled kernel since the kernel driver writers from the silicon vendor don't care about the bootloader (e.g. beaglebone). 
There are patches available to assign a static mac based on e.g. die IDs, but those aren't in mainine linux yet. And that's just for the 2 platforms I care for at $dayjob and I don't think they are the only ones.
It sucks, it's a bug and must be fixed, but right now you can't say 'hwaddresses does not change randomly' :(

regards,

Koen