Re: [gentoo-dev] Re: Request of news item review: 2013-03-29-udev-predictable-network-interface-names.en.txt

[Samuli Suominen]

On 29/03/13 18:21, Nuno J. Silva (aka njsg) wrote:
> On 2013-03-29, Diego Elio Pettenò <flameeyes@×××××××××.eu> wrote:
>> On 29/03/2013 12:34, Chí-Thanh Christopher Nguyễn wrote:
>>> Diego Elio Pettenò schrieb:
>>>>> If my desktop only has one Ethernet interface, no matter how many kernel
>>>>> changes happen, it'll always be eth0.
>>> That was not true with the old persistent naming. One example which we
>>> encountered in #gentoo IRC was the split between e1000 and e1000e drivers
>>> which caused interfaces to change names.
>>
>> Okay let me re-qualify the statement:
>>
>> "If my desktop only has one Ethernet interface, and I don't mess up with
>> it in userspace at all, no matter how many kernel changes happen, it'll
>> always be eth0".
>>
>> Yes, the previous persistent rules for udev would have messed that one
>> up when e1000e got split, or if you switched between the
>> Broadcom-provided driver to the kernel one or vice-versa. The deathforce
>> drivers come in mind as well.
>
> IMHO this is really relevant. It is annoying seeing how many people go
> "oh you *must not* use the old scheme, because it won't work".
>
> The new naming scheme does *not* prevent you from using eth0, users
> should really just be told they can *disable* udev rules (and told how
> to do it) if they are happy with the kernel name of their sole network
> card, instead of being told that they *must* upgrade to the new rules.
>
> The messages so far seem to imply that you can't have eth0. You *can*,
> but udev won't be able to do anything if the device appears as
> something else and there's already another eth0. If you don't already
> have eth0, the udev rules *will* work, even if your card is named in
> the eth namespace.
>
> The *only* thing that breaks is renaming network devices to names that
> are already in use inside the kernel namespaces.

I think you may have not seen the latest version, it says for eg.

"If you only have one interface card, you don't necessarily have much
use for this feature as the name almost always stays at eth0, you can
easily disable it using forementioned methods."

After first listing 3 different ways of disabling the new names earlier.

http://sources.gentoo.org/gitweb/?p=proj/gentoo-news.git;a=blob_plain;f=2013/2013-03-29-udev-upgrade/2013-03-29-udev-upgrade.en.txt;hb=HEAD

But I'd prefer not to lead people to the path of renaming into namespace 
already taken... that can lead to issues. It sounds almost as hackish as 
the script that frees the whole namespace by using temporary names:
https://bugs.gentoo.org/attachment.cgi?id=336774

Still trying to decipher people if there is more to adjust in the news 
though, it doesn't have to be frozen as is, if you have better wording, 
please provide a patch against the current. Thanks :)

- Samuli