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On Thu, 22 Dec 2016 04:15:50 +0100, lee wrote: |
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> > There are no config files to edit with the predictable names, the |
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> > names are created from the physical location of the port. That's why |
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> > they are called predictable, |
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> |
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> I only know what the names are when I can look them up when the computer |
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> is running. I don't call that "predictable". |
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If they are constructed according to specific rules, they are |
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predictable, by definition. |
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> They were much more predictable before because I could be reasonably |
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> sure that each of the ports would be called 'ethN', starting with N = 0, |
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"Reasonably sure" is not predictable. A lot of this stuff is designed to |
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make automated management easier, so editing rules or config files is |
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undesirable. It is more about being able to automatically provision and |
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configure new systems, whether hardware or virtual. |
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> unless I changed a card for a different one after an udev rule had |
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> already been created. |
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and being able to make changes without messing with the rest of your |
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system. I stand by my previous analogy of disk devices nodes vs UUIDs. |
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One is readable the other is safe. Yes, you can use filesystem labels, |
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which can be both, but that requires intervention, just like your udev |
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rules. That doesn't make either approach wrong, just suited to different |
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purposes. |
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> > unless you move the NIC to a different PCI slot, it will always have |
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> > the same name, no matter what other hardware you add or remove. Yes, |
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> > the names are cumbersome, but they have to be like that to guarantee |
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> > their uniqueness. |
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> |
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> You don't need to defend the unrecognisable names. The names used for |
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> referring to network ports don't need to be like that. |
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No they don't. It is merely one solution to the problem, and the names |
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are recognisable, Alan posted the key earlier. They are complex and may |
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look cryptic until you understand them, but so is English. |
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> The perceived advantage lies in being able to refer to network ports in |
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> a more reliable way, and I don't see how using unrecognisable names |
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> instead of recognisable ones would make anything easier. |
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See above re automation. It doesn't really matter whether you see the |
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need or not. If you don't have the need, don't use it, they are an |
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option for those who do want them. |
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> It would have made things easier if the problem had been solved by |
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> giving them recognisable names (or aliases) by default --- or even if |
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> the default names (aliases) were the same as the unrecognisable names |
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> --- and allowing to easily configure the names (aliases) actually used |
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> to refer to the ports. |
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That's a good point, and surely doable with udev rules, making the whole |
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argument moot. I haven't investigated because I don't have the need, but |
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I would be interested to hear what you discover. |
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and not that unrecognisable once you understand the systax. |
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> Being able to refer to things in more reliable ways improves the quality |
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> of the software. Using unrecognisable names for things reduces the |
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> quality. |
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They are reliable, unlike your "reasonably sure" approach, |
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> This is like you're defending a type of new pliers. |
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I'm not so much defending them and expressing an opinion. I can see the |
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benefits and the drawbacks. They are an option, albeit one that is turned |
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on by default (but since when have Gentoo users ever been bothered about |
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upstream defaults?). Portage even gives you explicit instuctions on how |
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to permanently disable them with a single command, although I generally |
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use the net.ifnames=0 kernel option instead on single NIC machines, where |
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the feature is pointless. |
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> But who knows, perhaps it is now possible to easily, on the fly, name |
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> the network ports through a neat configuration file. I'm merely asking |
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> if there is because I don't know and would find that very useful. |
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Can't ifrename do what you want? |
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> > How often you you have to type interface names anyway, and how many of |
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> > those are in a shell with tab completion that takes care of it for |
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> > you? |
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> |
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> None of them are, and I don't type the names. They require copy and |
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> paste, or very careful and tedious typing after looking them up. |
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Well, if you're scripting them, you only need to do it once per |
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interface, surely? That might be less work that setting up ifrename, but |
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use whatever works for you, your choices include, but are not restricted |
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to, and in no particular order. |
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|
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Learn how the predictable names work |
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Disable the feature entirely and hope the eth0 names work as expected |
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Use udev rules |
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Use ifrename |
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Some combination of the above. |
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-- |
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Neil Bothwick |
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...and that is how we know the Earth to be banana-shaped. |