My 0.02€ It's interesting how this topic is so often resurrected. The first time we upgraded a RedHat server and the network interfaces were renamed, our supervisor was.....angered :-) The issue is the order of enumeration of devices on a PCI bus. Even identical models of NIC at the same level of firmware will become ready in non-uniform ways. Temperature plays a role, etc. If the systemd designers (same as the udev guys, right?) made a mistake here, perhaps it was overreach.
On Sat, Mar 23, 2019, 1:20 PM Mart van de Wege <mvdw...@gmail.com> wrote: > Hans <hans.ullr...@loop.de> writes: > > > Am Freitag, 22. März 2019, 17:15:29 CET schrieb Reco: > >> Or, for instance, en0p2gibberish. They call them Unpredictable Device > >> Named for a reason. > >> > > > > Yes, thsis is another thing, which I am thinking of: The names could > change > > (in case, when there are more than one network devices are active or the > order > > of activing changed). > > No. Changes in the activation order or the number of devices do not > matter. The naming scheme is based on what bus the devices are on and > what position on that bus they hold[1]. Once a name is assigned, unless > you plug the card into a different slot, you will get the same name > (note that this may not apply on hotplug architectures that don't assume > fixed slot positions, like USB). > > It is the *old* way that lead to unpredictable renames unless you > implemented udev rules to hardcode names to e.g. MAC addresses. > > > In the past, I forced the order with persistent- net.rules. Dunno, if > > normal users can deal with it. Can it your Mom or your Dad? Grandpa? > > Grandma? > > > Is it any worse than expecting them to write a udev rule? > > In the end it is a hard problem to solve because the Linux kernel does > dynamic enumeration of devices, so you either need a deterministic > algorithm to assign a name (ask the firmware) or a userspace workaround > in identifying the device (e.g. using udev rules, or using UUIDs in > /etc/fstab, etc). > > Mart > > [1] OK, not *entirely* true, it's based on what the firmware reports as > the device position (it used to be called 'biosdevname'. Don't know if > that still is the name in these (U)EFI times). > > -- > "We will need a longer wall when the revolution comes." > --- AJS, quoting an uncertain source. > >
