Proposed F19 Feature: systemd/udev Predictable Network Interface Names

[Bill Nottingham]

Matthew Miller (mattdm at fedoraproject.org) said: 
> > But I guess we simply have a different definition of a user here. Your
> > definition is probably closer to what the page calls "admins", which is
> > covered by the next lines in the feature page, which you didn't paste:
> 
> Right. For Fedora, developers and admins are an important subset of users.
> 
> > "As biosdevname is installed by default ...  most administrators won't
> > see this either. "
> 
> If the new scheme really is better, we should suck it up and make the whole
> change. It'd be better to do what we can to make that transition easier --
> like using similar names were possible -- than to have a weird mixed state.

So, thinking - if we were to go this route, I think we'd want a clean
break, where we don't use biosdevname at all if we're using this.

The simplest way to do that would be:
- change biosdevname to not be installed by default
- enable these rules only on install, not on upgrade
both of which are pretty easily doable.

To quote the documentation, of the device name formats:

 * Two character prefixes based on the type of interface:
 *   en -- ethernet
 *   wl -- wlan
 *   ww -- wwan
 *
 * Type of names:
 *   o<index>                              -- on-board device index number
 *   s<slot>[f<function>][d<dev_id>]       -- hotplug slot index number
 *   x<MAC>                                -- MAC address
 *   p<bus>s<slot>[f<function>][d<dev_id>] -- PCI geographical location
 *   p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]
 *                                         -- USB port number chain

What concerns would people have with this naming? Off the top of my head:

- wwan devices aren't always discoverable (they can show up as ethernet)
- devices that biosdevname considers emX via enumeration/guessing would
  now have enpXsY, which could be considered 'uglier'

Bill