I suppose I should add this. In datacenters of a certain size, when the network cabling leaves control of the OS administrators (yes, even the Wintel admins), network admins aren't there to make your life easier. You do it yourself. I encountered the same issue with SAN admins a bit later over fiber cabling to my servers. If the OS adds complication you deal with it, even if you didn't have to before. You can argue that admins should have been explicitly configuring NICs with salt, cobbler, etc. We did.
On Sat, Mar 23, 2019, 2:30 PM Nicholas Geovanis <nickgeova...@gmail.com> wrote: > 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. >> >>
