CentOS - Feb 2020 - Renaming virtio devices names on CentOS 8 VM guest

I have built a CentOS 8 base image from a kickstart, for use in OpenStack.
This image boots fine but the problem I have is that I can't stop udev from
renaming the network device from eth0 to ens<something>.
I have /etc/sysconfig/network-scripts/ifcfg-eth0 with the correct HWADDR defined
in it, and have set net.ifnames=0 and biosdevname=0 in the grub configuration,
but nothing I have tried has stopped the renaming.
I found this bug: https://bugzilla.redhat.com/show_bug.cgi?id=1660179 which
describes the same situation, but the comments in the bug didn't help.
I'd like to keep the eth* device names because we have various heat
templates and other scripts which assume that the network devices are called
eth0, eth1 etc.
Any ideas? Is this even possible with a CentOS 8 VM guest?

Chris

On Fri, Feb 21, 2020 at 10:57 AM Chris Card <ctcard at hotmail.com> wrote:
> I have built a CentOS 8 base image from a kickstart, for use in OpenStack.
> This image boots fine but the problem I have is that I can't stop udev
> from renaming the network device from eth0 to ens<something>.
> I have /etc/sysconfig/network-scripts/ifcfg-eth0 with the correct HWADDR
> defined in it, and have set net.ifnames=0 and biosdevname=0 in the grub
> configuration, but nothing I have tried has stopped the renaming.
> I found this bug: https://bugzilla.redhat.com/show_bug.cgi?id=1660179
> which describes the same situation, but the comments in the bug didn't
help.
> I'd like to keep the eth* device names because we have various heat
> templates and other scripts which assume that the network devices are
> called eth0, eth1 etc.
> Any ideas? Is this even possible with a CentOS 8 VM guest?
>
> Chris
>
>
It is strongly discouraged, for Openstack and when you have more than one
adapter. See here if you have access:
https://access.redhat.com/solutions/2435891

Anyway perhaps you could manage order of names customizing
/usr/lib/systemd/network/99-default.link
At least as described here:
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/consistent-network-interface-device-naming_configuring-and-managing-networking
but I never tried it
HIH,
Gianluca

Thanks Gianluca,

I can't access https://access.redhat.com/solutions/2435891 unfortunately,
but
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/consistent-network-interface-device-naming_configuring-and-managing-networking
looks like it might help me.

Chris


________________________________
From: CentOS <centos-bounces at centos.org> on behalf of Gianluca Cecchi
<gianluca.cecchi at gmail.com>
Sent: 21 February 2020 12:03
To: CentOS mailing list <centos at centos.org>
Subject: Re: [CentOS] Renaming virtio devices names on CentOS 8 VM guest

On Fri, Feb 21, 2020 at 10:57 AM Chris Card <ctcard at hotmail.com> wrote:
> I have built a CentOS 8 base image from a kickstart, for use in OpenStack.
> This image boots fine but the problem I have is that I can't stop udev
> from renaming the network device from eth0 to ens<something>.
> I have /etc/sysconfig/network-scripts/ifcfg-eth0 with the correct HWADDR
> defined in it, and have set net.ifnames=0 and biosdevname=0 in the grub
> configuration, but nothing I have tried has stopped the renaming.
> I found this bug: https://bugzilla.redhat.com/show_bug.cgi?id=1660179
> which describes the same situation, but the comments in the bug didn't
help.
> I'd like to keep the eth* device names because we have various heat
> templates and other scripts which assume that the network devices are
> called eth0, eth1 etc.
> Any ideas? Is this even possible with a CentOS 8 VM guest?
>
> Chris
>
>
It is strongly discouraged, for Openstack and when you have more than one
adapter. See here if you have access:
https://access.redhat.com/solutions/2435891

Anyway perhaps you could manage order of names customizing
/usr/lib/systemd/network/99-default.link
At least as described here:
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/consistent-network-interface-device-naming_configuring-and-managing-networking
but I never tried it
HIH,
Gianluca
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CentOS at centos.org
https://lists.centos.org/mailman/listinfo/centos

On Fri, 2020-02-21 at 13:03 +0100, Gianluca Cecchi
wrote:
> On Fri, Feb 21, 2020 at 10:57 AM Chris Card <ctcard at hotmail.com>
> wrote:
> 
> > I have built a CentOS 8 base image from a kickstart, for use in
> > OpenStack.
> > This image boots fine but the problem I have is that I can't stop
> > udev
> > from renaming the network device from eth0 to ens<something>.
> > I have /etc/sysconfig/network-scripts/ifcfg-eth0 with the correct
> > HWADDR
> > defined in it, and have set net.ifnames=0 and biosdevname=0 in the
> > grub
> > configuration, but nothing I have tried has stopped the renaming.
> > I found this bug: 
> > https://bugzilla.redhat.com/show_bug.cgi?id=1660179
> > which describes the same situation, but the comments in the bug
> > didn't help.
> > I'd like to keep the eth* device names because we have various
heat
> > templates and other scripts which assume that the network devices
> > are
> > called eth0, eth1 etc.
> > Any ideas? Is this even possible with a CentOS 8 VM guest?
> > 
> > Chris
> > 
> > 
> It is strongly discouraged, for Openstack and when you have more than
> one
> adapter. See here if you have access:
> https://access.redhat.com/solutions/2435891
> 
> Anyway perhaps you could manage order of names customizing
> /usr/lib/systemd/network/99-default.link
> At least as described here:
>
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/consistent-network-interface-device-naming_configuring-and-managing-networking
> but I never tried it
> HIH,
> Gianluca
Gianluca,

What you are trying to do is documented at 
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/networking_guide/sec-disabling_consistent_network_device_naming

You need to edit the GRUB_CMDLOINE_LINUX line in /etc/default/grub as
shown below;

~]# cat /etc/default/grub
    GRUB_TIMEOUT=5
    GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g'
/etc/system-release)"
    GRUB_DEFAULT=saved
    GRUB_DISABLE_SUBMENU=true
    GRUB_TERMINAL_OUTPUT="console"
    GRUB_CMDLINE_LINUX="rd.lvm.lv=rhel_7/swap rd.luks.uuid=luks-
cc387312-6da6-469a-8e49-b40cd58ad67a
crashkernel=auto  vconsole.keymap=us vconsole.font=latarcyrheb-sun16
rd.lvm.lv=rhel_7/root rhgb quiet net.ifnames=0 biosdevname=0"
    GRUB_DISABLE_RECOVERY="true"

Then for an EUFI system run this:
~]# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
Reboot and you should have your old eth0, eth1, etc. naming convention
back again.  WATCH YOUR TYPING. BE CAREFUL NOT TO OMIT OR ADD
EXTRANEOUS SPACES !!!
Hope this helps.
--Doc Savage    Fairview Heights, IL 62208-3432