Dan McGhee wrote: > On 11/26/2013 07:53 AM, William Harrington wrote: >> On Nov 25, 2013, at 8:06 PM, Dan McGhee wrote: >> >>> There were many allusions to the "new naming convention." enpxx for >>> ethernet and wlpxx for wireless. Where does this name convention >>> exist? I remember that xlnglp posted about what he had discovered in >>> the "different" names, but I can't find what he wrote. I don't >>> remember >>> if he had identified a source. >> Possibly it came from here: >> http://fedoraproject.org/wiki/Features/ConsistentNetworkDeviceNaming >> >> Check out biosdevname >> >> Sincerely, >> >> William Harrington > Thanks, William. That link led down an interesting path. It appears that > this "name thing" originated at Dell. I don't know if the fellow who > came up with the idea is a maintainer for UDEV or not. Anyway, The above > link led me to this: > > http://marc.info/?l=linux-hotplug&m=128892593821639&w=2 > > It is an interesting discussion on how to implement or cancel the "name > thing" in udev. This, and William's suggestion, led me to "biosdevname." > It is a utility to take a kernel device name and return "the BIOS-given > name it 'should' be." (That from the biosdevname man page.) > [semi-rant]There is no indication of the identity of the "true BIOS name > giver."[/semi-rant] > > Also from the biosdevname man page: > >> The *physical* policy is the current default. However, when invoking >> biosdevname in udev rules, one should always specify the policy you >> want, as the default has changed over time. >> The *physical* policy uses the following scheme: >> >> em<port>[_<virtual instance>] >> for embedded NICs p<slot>p<port>[_<virtual instance>] >> for cards in PCI slots >> The >> *all_ethN* policy makes a best guess at what the device order >> should be, with embedded devices first, PCI cards in ascending >> slot order, and ports in ascending PCI bus/device/function order >> breadth-first. However, this policy /does/ not work if your PCI >> devices are hot-plugged or hot-pluggable, including the virtual >> functions on an SR-IOV device. In a hot-plug scenario, each >> separate udev instance will be invoked in parallel, while the >> device tree is still being populated with new devices. Each udev >> instance will see a different PCI tree, and thus cannot provide >> consistent enumeration. Use of this policy should be limited to >> only scenarios where all PCI devices are present at boot (cold-plug). >> > > So, it appears that this "name thing" is a "udev thing" and not a > "kernel thing." If my conclusions are correct, then I still wonder why > Alan's NIC, which is the same as mine, got a different name. The only > difference I know of so far is that he used LFS_SVN and I used LFS-7.4. > I'm discounting the kernel difference. I don't know if there's any > difference in results between UDEV-206 (LFS-7.4) and UDEV-208(LFS-SVN). > The only other possible difference is that Alan may have added "UDEV > Extras from BLFS.
The difference could be the motherboard architecture or the slot the Ethernet is plugged into. > On the other hand, I can understand another possible difference unless I > don't understand what "hot-plug" means. To me it's the ability to "plug > something in" while the computer is running and have it work--much like > a USB device. If my NIC is hot-pluggable, I would have to open the > laptop case to remove it. There are such things as USB Ethernet adapters. I'm not sure how useful they are today. Perhaps some tablets have USB but not a Ethernet socket. -- Bruce -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
