Matthew Miller (mattdm(a)fedoraproject.org) said:
On Wed, Jan 23, 2013 at 07:59:07PM +0000, Jaroslav Reznik wrote:
> The udevd service has a long history of providing predicatable names for
> block devices and others. For Fedora 19 we'd like to provide the same for
> network interfaces, following a similar naming scheme, but only as
> fallback if not other solution such as biosdevname is installed or the
> administrator manually defined network interface names via udev rules or
> the old network scripts.
[...]
> This feature is about enabling this as default in Fedora, but only as a
> fallback if the user/administrator did not manually assign names to interfaces
> via udev rules, or via the old networking scripts, or if biosdevname is
> installed.
This seems to invent yet another new naming scheme. We just went through
this pain, and the biosdevname scheme went through several iterations in the
field and represents real-world lessons learned. Is there a compelling
reason to make the systemd/udev policy for Fedora not just follow the
existing solution to the same problem embodied in biosdevname? (Then, we
could just phase out biosdevname.)
biosdevname naming isn't apparently consistent across versions.
https://bugzilla.redhat.com/show_bug.cgi?id=782145#c21
The problems are roughly this:
- biosdevname only provides predictable naming for machines with SMBIOS
type 9 & type 41 records
- For other machines, it does 'best effort' based off of heuristics and
attempting to enumerate all the devices... which gives weird/unpredictable
results.
This code has the benefit of:
- covering more device types (not just BIOSes with type 9 & type 41)
- not attempting to do heuristics that name devices via enumeration
However, it does have the large disadvantage of changing the namespace used.
Bill