:: Re: [DNG] Beowulf Beta is here!
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Szerző: Didier Kryn
Dátum:  
Címzett: dng
Tárgy: Re: [DNG] Beowulf Beta is here!
Le 10/04/2020 à 00:19, aitor_czr a écrit :
>
> Hi Didier,
>
> On 4/9/20 4:29 PM, Didier Kryn wrote:
>> Le 09/04/2020 à 18:16, Didier Kryn a écrit :
>>> Le 09/04/2020 à 16:13, dal a écrit :
>>>> Hello and thanks for Beowulf.
>>>>
>>>> An issue:
>>>>
>>>> it looks like
>>>>
>>>>    devuan_beowulf_3.0.0_beta_amd64_netinstall.iso
>>>>    and the base system installable from it
>>>>
>>>> do not contain the ifupdown package (nor other networking utilities
>>>> besides busybox ip?).
>>>>
>>>> The resulting base installation remains offline.
>>>> This is a more limited definition of a "base system" than it used
>>>> to be, most probably unintentionally.
>>>
>>>     I remember this was also the case in a previous version, wether
>>> Jessie or Ascii. Obviously this isn't an issue when upgrading. I
>>> also remind you that the startup delay caused by the timed-out
>>> activation of the Ethernet interface (when not plugged in) is still
>>> there with the default interfaces file. The solution is to remove
>>> the clause "allow-hotplug eth0" and install ifupdown or the
>>> equivalent I have forgotten the name of.
>>     Sorry for the typo. install *ifplugd* or an equivalent.
> After a reboot the network devices are properly brought up using
> different options like *auto*,
> *allow-auto* or *allow-hotplug*.The differences between them are:
>
> 1) auto <device> - This stanza in /etc/network/interfaces file starts
> the network interface at boot
> (this is the option used by the loopback virtual interface).
>
> 2) allow-auto <device> - Similar to the first one. I'm not pretty sure
> if there is any difference.
>
> 3) allow-hotplug <device> -  As opposed to the others, it starts when
> a *plug* event is detected.
> The fact that it'll will be waiting for eventslike the linking of the
> ethernet cable or something that
> involveskernel/eudev detection against the hardware, can lead us to
> think that thiskind of linking
> configurationis the guiltyof the delay during the boot process, but
> this is only a half-truth.


    After experimenting I think I can state that "hotplug" here means
that the interface itself - not the cable - can be hotplugged. This is
usefull if you plug in a USB-Ethernet adapter. It has nothing to do with
detecting the connection of an Ethernet cable. If your Ethernet
interface is hard-wired, the "auto" stanza has the same effect.Once the
Ethernet interface is detected, the logic of ifupdown is to bring it up,
and then it enters a timed-out wait for the carrier.

    f you have several interfaces, ifupdown will try to bring them up
one after the other with a timed-out wait for the carrier. In general on
a laptop, you have one Ethernet and one Wifi, both hardwired. You can
put an "auto" or "allow-hotplug" stanza for the Wifi because it will be
tried last. If you have an "allow-hotplug" for the Ethernet and the
cable is not connected, it will just add a delay to the startup but it
will not allow the detection of the carrier when an Ethernet cable is
connected; you need something like ifplugd for that.

        Didier