15.04 and systemd

Tom H tomh0665 at gmail.com
Sat Dec 13 11:16:18 UTC 2014

On Sun, Dec 7, 2014 at 2:11 AM, Martin Pitt <martin.pitt at ubuntu.com> wrote:
> Tom H [2014-12-05  8:03 -0500]:
>>> | $ grep ifup /lib/udev/rules.d/99-systemd.rules
>>> | SUBSYSTEM=="net", KERNEL!="lo", TAG+="systemd", ENV{SYSTEMD_ALIAS}+="/sys/subsystem/net/devices/$name", ENV{SYSTEMD_WANTS}+="ifup@$name.service"
>> I noticed this after sending my original email. I'm now using NM (I
>> had to log on to a WEP network!) and I'd meant to check whether
>> unmasking ifup at .service would result in the same errors because this
>> rule doesn't have "check whether something other than ifupdown is
>> bringing up the network" (if that's even possible in a udev rule).
> The rule doesn't have to. ifup will know by itself (through
> /etc/network/interfaces) if it's responsible for a particular
> interface; if not, this is a no-op.
>>> This will handle hotplugged interfaces which are covered by ifupdown,
>>> i. e. /etc/network/interfaces.
>> Except that my "interfaces" file's empty.
> Right, then the rule and ifup at .service are irrelevant for your system.
> This is also why the disabled /etc/init.d/networking init script did
> not cause acual damage on your system. systemd brings up lo on its
> own, so you don't need ifupdown for "lo" even.
>> By hotplugged do you mean when using Debian's "allow-hotplug"?
> I meant "added the hardware while the computer/user session is
> running". "allow-hotplug" is Debian's ifupdown declaration for this
> (but not supported directly under Ubuntu).
>> I hadn't seen the ifup udev rule when I wrote the above so I thought
>> that systemd was using the sysvinit networking script to trigger
>> ifup at .service.
> The sysvinit script is called at boot to bring up the non-hotplugged
> interfaces (lo, builtin ethernet or wifi cards), if they are tagged as
> "auto".

>> I'll set up a VM to try to reproduce this.
>> Do you mean upgrade trusty-to-utopic or utopic-to-vivid?
> Well, finding out the upgrade path that causes /etc/init.d/networking
> to be disabled is exactly the exercise :-) It might just be "clean
> utopic install and upgrade to vivid", but it might be more complicated
> than that.

Many thanks for your answers. I'll only answer your last para because
we're misunderstanding one another and I don't want to add yet another
layer of misunderstanding!

I'd installed 15.04 from a daily/nighly ISO and disabled networking
manually. There was no automatic/hidden disabling.

I set up a utopic VM and upgraded it to vivid.

I didn't disable networking or mask ifup@ for either and I didn't get
the errors that I'd reported in my initial email. I've also unmasked
ifup@ on my laptop and I'm no longer getting these errors.

Since I was getting these errors at every boot with v216, I have to
assume that the problem's been fixed with the upgrade to v217.
Apologies for the noise.

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