[gentoo-user] eudev/udev changeover: a warning to Linode customers

[gentoo-user] eudev/udev changeover: a warning to Linode customers

[Matt Connell (Gmail)]

If you have a Gentoo machine running on Linode, take care to note that
the eudev => udev changeover requires some manual intervention before
the next reboot.

You will need to DISABLE the network autoconfiguration option for the
VM, and edit /etc/conf.d/net to specify the new, 'predictable' network
interface name.  This is because Linode's network autoconfigurator is
hard-coded to generate a configuration using the traditional style of
network interface names, eg. eth0 

Alternatively, you can make whatever changes are required to have the
system enumerate the network interfaces with the old style names.

If you do neither of those things, you will need to use the rescue
console in order to log into the machine and fix your network
configuration, as the system will not be able to bring up the network
on its next boot.  Ask me how I learned this.

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Jigme Datse]

On Wed, 01 Dec 2021 12:49:59 -0500
"Matt Connell (Gmail)" <matthewdconnell@gmail.com> wrote:

> If you have a Gentoo machine running on Linode, take care to note that
> the eudev => udev changeover requires some manual intervention before
> the next reboot.
> 
> You will need to DISABLE the network autoconfiguration option for the
> VM, and edit /etc/conf.d/net to specify the new, 'predictable' network
> interface name.  This is because Linode's network autoconfigurator is
> hard-coded to generate a configuration using the traditional style of
> network interface names, eg. eth0 
> 
> Alternatively, you can make whatever changes are required to have the
> system enumerate the network interfaces with the old style names.
> 
> If you do neither of those things, you will need to use the rescue
> console in order to log into the machine and fix your network
> configuration, as the system will not be able to bring up the network
> on its next boot.  Ask me how I learned this.
> 
> 

I honestly was afraid of this with running some updates lately.
Like...  Not this specifically, but because someone was commenting
about eudev->udev causing problems...  And then the problems I was
having a hard time with some updates on a relatively new instance, and
I noticed that was something that needed to be done for Gentoo
purposes...  They do seem to be doing *somewhat* better for having
Gentoo workable than when I started looking at using them in part
because of that (yeah I know it's not recommended, and I don't really
recommend it for anyone else, but it's what I like).

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Rich Freeman]

On Wed, Dec 1, 2021 at 2:17 PM Jigme Datse
<jigme.datse@datsemultimedia.com> wrote:
>
> I honestly was afraid of this with running some updates lately.
> Like...  Not this specifically, but because someone was commenting
> about eudev->udev causing problems...  And then the problems I was
> having a hard time with some updates on a relatively new instance, and
> I noticed that was something that needed to be done for Gentoo
> purposes...  They do seem to be doing *somewhat* better for having
> Gentoo workable than when I started looking at using them in part
> because of that (yeah I know it's not recommended, and I don't really
> recommend it for anyone else, but it's what I like).
>

I suspect they would have had similar issues with other distros, but
that would have been years ago when udev made the change and eudev
decided not to merge it.  That dates to around the time eudev started.

They may very well have done more hand-holding or mitigation for the
other distros simply due to their popularity, and also uniformity.
The distros themselves probably also did some mitigation around this
change so that the average Ubuntu user who doesn't know what an "eth0"
is wouldn't have to be aware of the change.

With Gentoo a certain amount of this stuff just has to be dropped on
the user simply because we can't be sure users didn't change things,
and indeed being able to change this stuff is part of the appeal of
Gentoo.  Besides, Gentoo users probably would want to be aware of it
anyway...

-- 
Rich

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Matt Connell (Gmail)]

On Wed, 2021-12-01 at 14:28 -0500, Rich Freeman wrote:
> indeed being able to change this stuff is part of the appeal of
> Gentoo.  Besides, Gentoo users probably would want to be aware of it
> anyway...

Amen.  I knew what I was signing up for.  Just hoping to save someone
else an unexpected trip through the recovery console.  Learning things
the hard way so that others won't have to!

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Arve Barsnes]

On Wed, 1 Dec 2021 at 20:28, Rich Freeman <rich0@gentoo.org> wrote:
> I suspect they would have had similar issues with other distros, but
> that would have been years ago when udev made the change and eudev
> decided not to merge it.  That dates to around the time eudev started.

I have been running eudev for as long as it has existed, and have also
been using the predictable interface names more or less since they
were introduced. The eudev ebuild also shows a message about this
every single time you emerge it (with ewarn messages in pkg_pretend).
This was apparently available in eudev within a month of the change in
systemd. No one should be surprised by this.

Cheers,
Arve

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Marco Rebhan]

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On Wednesday, 1 December 2021 20:44:48 CET Arve Barsnes wrote:
> I have been running eudev for as long as it has existed, and have also
> been using the predictable interface names more or less since they
> were introduced. The eudev ebuild also shows a message about this
> every single time you emerge it (with ewarn messages in pkg_pretend).
> This was apparently available in eudev within a month of the change
> in systemd. No one should be surprised by this.

Yeah, I was wondering why people were hitting this problem, the 
predictable interface names have been in eudev as well for a 
considerable while. I had them disabled with the same net.ifnames=0 that 
others are mentioning now to get the old names (mainly since they're 
just easier to remember). I was maybe thinking that there could be a 
configuration option for it that didn't get changed on existing installs 
when this was initially introduced in eudev, which would have explained 
it since my installs aren't that old. But if it automatically used the 
new names for you then I have no idea either. Nothing should have 
changed in this regard with this update as far as I can tell...

-Marco

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Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Dale]

Marco Rebhan wrote:
> On Wednesday, 1 December 2021 20:44:48 CET Arve Barsnes wrote:
>> I have been running eudev for as long as it has existed, and have also
>> been using the predictable interface names more or less since they
>> were introduced. The eudev ebuild also shows a message about this
>> every single time you emerge it (with ewarn messages in pkg_pretend).
>> This was apparently available in eudev within a month of the change
>> in systemd. No one should be surprised by this.
> Yeah, I was wondering why people were hitting this problem, the 
> predictable interface names have been in eudev as well for a 
> considerable while. I had them disabled with the same net.ifnames=0 that 
> others are mentioning now to get the old names (mainly since they're 
> just easier to remember). I was maybe thinking that there could be a 
> configuration option for it that didn't get changed on existing installs 
> when this was initially introduced in eudev, which would have explained 
> it since my installs aren't that old. But if it automatically used the 
> new names for you then I have no idea either. Nothing should have 
> changed in this regard with this update as far as I can tell...
>
> -Marco


What made this affect me, I think the method is different to disable it
in udev than it is in eudev.  I had something set, not on the kernel
line tho, to disable it on mine when using eudev.  I think it is a udev
rules file.  Thing is, when I rebooted with udev installed, it ignored
the method eudev uses and used the newer naming method.  If the same
option worked for both, then I would likely have seen no difference at
all.  I might add, that is what I was expecting and was surprised to
find it not to be the case.  When I switched from udev to eudev ages
ago, I did nothing but remove udev and install eudev.  That's it.  I
don't recall changing anything else but that was ages ago. 

I'm hoping others doing this switch will notice my thread and this
thread to prevent them from switching and not realizing it can break
things until it is configured correctly.  Bad thing is, it breaks one
thing that is needed to get help, the connection to the internet.  If it
is a remote machine, that is really bad.

Let's hope this alerts others to double and maybe even triple check
things before rebooting. 

Dale

:-)  :-) 

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Neil Bothwick]

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On Wed, 1 Dec 2021 17:27:32 -0600, Dale wrote:

> What made this affect me, I think the method is different to disable it
> in udev than it is in eudev.

net.ifnames=0 works on both udev and eudev, I've had it in my GRUB config
for years and it needed no changes when switching from eudev to udev.


-- 
Neil Bothwick

There are some micro-organisms that exhibit characteristics of both
plants and animals.  When exposed to light they undergo photosynthesis;
and when the lights go out, they turn into animals.  But then again,
don't we all?

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Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Dale]

Neil Bothwick wrote:
> On Wed, 1 Dec 2021 17:27:32 -0600, Dale wrote:
>
>> What made this affect me, I think the method is different to disable it
>> in udev than it is in eudev.
> net.ifnames=0 works on both udev and eudev, I've had it in my GRUB config
> for years and it needed no changes when switching from eudev to udev.
>
>


I'm pretty sure mine is done with a udev rules file.  I never had mine
on the kernel line.  This is the list of rules files I have:


root@fireball / # ls -al /etc/udev/rules.d/
total 20
drwxr-xr-x 2 root root 4096 Nov 28 13:29 .
drwxr-xr-x 4 root root 4096 Nov 28 13:29 ..
-rw-r--r-- 1 root root 2064 Apr 27  2021 69-libmtp.rules
-rw-r--r-- 1 root root 1903 Apr  4  2012 70-persistent-cd.rules
-rw-r--r-- 1 root root  814 Jan  1  2008 70-persistent-net.rules
-rw-r--r-- 1 root root    0 Mar 22  2015 80-net-name-slot.rules
-rw-r--r-- 1 root root    0 Nov 27 17:53 .keep_sys-fs_udev-0
root@fireball / #


I can't recall which of the two about net it is tho.  Thing is, it seems
to work with eudev but not udev.  I'd think it would but based on
experience, it doesn't.  I guess if someone is switching a remote
machine, or any machine, and they want to be sure, add the option to the
kernel line to be safe.  That may be a more dependable method.

Either way, at least maybe these threads will help someone else avoid
the problem. 

Dale

:-)  :-)

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[John Covici]

On Wed, 01 Dec 2021 19:15:36 -0500,
Dale wrote:
> 
> Neil Bothwick wrote:
> > On Wed, 1 Dec 2021 17:27:32 -0600, Dale wrote:
> >
> >> What made this affect me, I think the method is different to disable it
> >> in udev than it is in eudev.
> > net.ifnames=0 works on both udev and eudev, I've had it in my GRUB config
> > for years and it needed no changes when switching from eudev to udev.
> >
> >
> 
> 
> I'm pretty sure mine is done with a udev rules file.  I never had mine
> on the kernel line.  This is the list of rules files I have:
> 
> 
> root@fireball / # ls -al /etc/udev/rules.d/
> total 20
> drwxr-xr-x 2 root root 4096 Nov 28 13:29 .
> drwxr-xr-x 4 root root 4096 Nov 28 13:29 ..
> -rw-r--r-- 1 root root 2064 Apr 27  2021 69-libmtp.rules
> -rw-r--r-- 1 root root 1903 Apr  4  2012 70-persistent-cd.rules
> -rw-r--r-- 1 root root  814 Jan  1  2008 70-persistent-net.rules
> -rw-r--r-- 1 root root    0 Mar 22  2015 80-net-name-slot.rules
> -rw-r--r-- 1 root root    0 Nov 27 17:53 .keep_sys-fs_udev-0
> root@fireball / #
> 
> 
> I can't recall which of the two about net it is tho.  Thing is, it seems
> to work with eudev but not udev.  I'd think it would but based on
> experience, it doesn't.  I guess if someone is switching a remote
> machine, or any machine, and they want to be sure, add the option to the
> kernel line to be safe.  That may be a more dependable method.
> 
> Either way, at least maybe these threads will help someone else avoid
> the problem. 

I had this happen to me when I got this box, the 80.rules hack stopped
working, and so I gave up and used the "predictable" names.  I must
have forgotten about the kernel command line parameter at the time.

-- 
Your life is like a penny.  You're going to lose it.  The question is:
How do
you spend it?

         John Covici wb2una
         covici@ccs.covici.com

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Rich Freeman]

On Wed, Dec 1, 2021 at 7:15 PM Dale <rdalek1967@gmail.com> wrote:
>
>
> root@fireball / # ls -al /etc/udev/rules.d/
> -rw-r--r-- 1 root root 1903 Apr  4  2012 70-persistent-cd.rules
> -rw-r--r-- 1 root root  814 Jan  1  2008 70-persistent-net.rules
> -rw-r--r-- 1 root root    0 Mar 22  2015 80-net-name-slot.rules
>
> I can't recall which of the two about net it is tho.  Thing is, it seems
> to work with eudev but not udev.

With udev the filenames you want are:
80-net-name-slot.rules
80-net-setup-link.rules

Or at least, that is what I am using with the systemd-bundled udev and
my physical interface is eth0.

-- 
Rich

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Rich Freeman]

On Wed, Dec 1, 2021 at 8:05 PM Rich Freeman <rich0@gentoo.org> wrote:
>
> On Wed, Dec 1, 2021 at 7:15 PM Dale <rdalek1967@gmail.com> wrote:
> >
> >
> > root@fireball / # ls -al /etc/udev/rules.d/
> > -rw-r--r-- 1 root root 1903 Apr  4  2012 70-persistent-cd.rules
> > -rw-r--r-- 1 root root  814 Jan  1  2008 70-persistent-net.rules
> > -rw-r--r-- 1 root root    0 Mar 22  2015 80-net-name-slot.rules
> >
> > I can't recall which of the two about net it is tho.  Thing is, it seems
> > to work with eudev but not udev.
>
> With udev the filenames you want are:
> 80-net-name-slot.rules
> 80-net-setup-link.rules
>
> Or at least, that is what I am using with the systemd-bundled udev and
> my physical interface is eth0.

Disregard that.  I'm also using net.ifnames=0 - I'm guessing the
filename changed at some point.  You probably can dig around in the
package-supplied udev rules to figure out which one needs to be
overridden now.

-- 
Rich

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Neil Bothwick]

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On Wed, 1 Dec 2021 20:07:11 -0500, Rich Freeman wrote:

> > With udev the filenames you want are:
> > 80-net-name-slot.rules
> > 80-net-setup-link.rules
> >
> > Or at least, that is what I am using with the systemd-bundled udev and
> > my physical interface is eth0.  
> 
> Disregard that.  I'm also using net.ifnames=0 - I'm guessing the
> filename changed at some point.  You probably can dig around in the
> package-supplied udev rules to figure out which one needs to be
> overridden now.

I'm not using any udev rules for network devices. If all you want is the
old eth?/wlan? names back the kernel parameter is sufficient. This works
with openrc and systemd here.


-- 
Neil Bothwick

Consciousness: that annoying time between naps.

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Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Rich Freeman]

On Thu, Dec 2, 2021 at 3:01 AM Neil Bothwick <neil@digimed.co.uk> wrote:
>
> On Wed, 1 Dec 2021 20:07:11 -0500, Rich Freeman wrote:
>
> >
> > Disregard that.
>
> I'm not using any udev rules for network devices. If all you want is the
> old eth?/wlan? names back the kernel parameter is sufficient. This works
> with openrc and systemd here.

Hence the reason I said "disregard that."

-- 
Rich

Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Neil Bothwick]

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On Thu, 2 Dec 2021 07:04:26 -0500, Rich Freeman wrote:

> > > Disregard that.  
> >
> > I'm not using any udev rules for network devices. If all you want is
> > the old eth?/wlan? names back the kernel parameter is sufficient.
> > This works with openrc and systemd here.  
> 
> Hence the reason I said "disregard that."

So what were your udev rules doing?


-- 
Neil Bothwick

I spilled Spot remover on my dog. Now he's gone.

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Re: [gentoo-user] eudev/udev changeover: a warning to Linode customers

[Rich Freeman]

On Thu, Dec 2, 2021 at 10:14 AM Neil Bothwick <neil@digimed.co.uk> wrote:
>
> On Thu, 2 Dec 2021 07:04:26 -0500, Rich Freeman wrote:
>
> > > > Disregard that.
> > >
> > > I'm not using any udev rules for network devices. If all you want is
> > > the old eth?/wlan? names back the kernel parameter is sufficient.
> > > This works with openrc and systemd here.
> >
> > Hence the reason I said "disregard that."
>
> So what were your udev rules doing?

Most likely, nothing.  In the past they disabled predictable interface names.

-- 
Rich