[ale] eth numbering change

[agcarver+ale at acarver.net (Alex Carver)]

On 2017-02-09 09:15, Phil Turmel wrote:
> On 02/08/2017 05:02 PM, Brian Stanaland wrote:
>> There were no udev rules in place. We set that up so the NICs were named
>> the way they wanted. It's possible that the motherboards were from
>> different production runs. The wired order of the slots isn't something
>> we would specify.
>>
>> That answers the question for me.
> 
> Well, not necessarily.  The wired order is often the most significant
> factor, but the kernel is free to probe asynchronously nowadays.  The
> slightest hiccup in the normal "eth0" driver could delay it long enough
> for the "eth1" device to initialize first, flipping the "natural" order.
> 
> This is also true for hard drives.  And all of this is precisely the
> reason udev persistent name rules were created, and blkid label and uuid
> names are used.
> 
> Don't use ethX names with modern kernels.  Period.
> 
> Phil

I wouldn't say never.  I had one installation that steadfastly refused
to boot properly with UUIDs for the disk.  It was a very recent kernel,
too, which made it much more confusing.  I had to force it back to using
/dev/sdAN references to get things working.