[CentOS] Renaming virtio devices names on CentOS 8 VM guest

Fri Feb 21 16:42:07 UTC 2020
Chris Card <ctcard at hotmail.com>

Thanks Robert,
I was doing that but it was still renaming to ens*.
However, I now know why, and have fixed it.
For those who are interested, the problem was that when I created the base image from a kickstart I didn't pass net.ifnames=0 to virt-create, and I ended up with an image that had forgotten about eth0 completely. I have now redone the kickstart with net.ifnames=0 and all is well.

Chris


Sent from Samsung Mobile on O2


-------- Original message --------
From: "Robert G (Doc) Savage via CentOS" <centos at centos.org>
Date: 21/02/2020 16:08 (GMT+00:00)
To: CentOS mailing list <centos at centos.org>
Subject: Re: [CentOS] Renaming virtio devices names on CentOS 8 VM guest

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
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