On Thu, Feb 16, 2017 at 12:47:25PM +0100, Christian Seiler wrote: > On a system with predictable names running? Or on a system > pre-upgrade? > > Because if you have a system that's being upgraded at the > moment, the following command _might_ work _after_ you've > upgraded udev and _before_ you've rebooted the system. > > udevadm info /sys/class/net/eth4 > > Look at ID_NET_NAME there. > > Can't really test that though, since I don't have a setup > with the old scheme that I still need to upgrade, so this > might not work at all.
I'm a bit confused here. On a system that's upgraded from jessie to stretch, why would the interface names change at all? The old eth0 style names are recorded in /etc/udev/rules.d/70-persistent-net.rules and the interfaces continue to come up as eth0, etc. Are you talking about a scenario where you upgrade to stretch and then add a new NIC? But even then it still wouldn't make sense, because you wouldn't have had a previous "eth4" name that you want to map to a new name. You'd just get the new name. Or are you talking about a hypothetical scenario where you upgrade to stretch and then remove the contents of /etc/udev/rules.d/70-persistent-net.rules, but before you do that, you want to see what the interfaces will become? That seems... quite odd to me. Why not just leave the interfaces alone?
