On Wednesday 23 December 2020 at 23:41:58, Didier Kryn wrote:
> Le 23/12/2020 à 22:03, Antony Stone a écrit :
> > If the kernel decides A=eth1, B=eth2, C=eth0 then there's no way for udev
> > rules to rename them, because "File exists" (which should of course say
> > "Device name exists").
>
> This should not happen and did not happen in the past because the
> interfaces are created sequentially. Therefore, if you want to rename
> the first one, no name other than eth0 exists yet; and you can figure
> out that something similar happen to the next: the kernel does not name
> it by the name you have assigned to the first one, etc.
No; the problem is that the kernel names all of the interfaces before udev
gets to do whatever it wants to, therefore by the time my rules saying which
interface I want as eth0, which as eth1 and which as eth2 are able to run, all
those names exist, but on the wrong (according to me) devices.
> What may have changed is Eudev managed to not work sequentially. If
> it followed the order in which the interfaces show up out of the
> Netlink, there would be no problem. Therefore I suspect the authors
> managed to launch several threads in order to save 0.01s of the boot
> time. Or to loose more because thread scheduling might well consume more
> than what parallelism saves.
I have no opinion on that.
> Or maybe the kernel is much faster than Eudev and it has the time to
> create the interfaces faster than Eudev processes them.
That sounds likely.
> But for sure the mechanism worked in the past.
I completely agree.
As I said in my opening posting on the "Ethernet names revisited" thread:
| I'm trying to work out how to give those interfaces the names I want; the
| motherboard as eth0, and the PCI card as eth1 / eth2.
|
| Historically, I've been used to udev and /etc/udev/rules.d/70-persistent-
| net.rules doing this, where I can specify the name I want for each interface
| according to its MAC address.
By "historically" I meant "up to Jessie, and I think also Stretch / Ascii".
It's not doing the same in Buster / Beowulf.
Antony.
--
I still maintain the point that designing a monolithic kernel in 1991 is a
fundamental error. Be thankful you are not my student. You would not get a
high grade for such a design :-)
- Andrew Tanenbaum to Linus Torvalds
Please reply to the list;
please *don't* CC me.
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