The Dell system does not use the `biosdevname` scheme by default in RHEL 8 and 9

Solution Verified - Updated

Environment

  • Red Hat Enterprise Linux 9
  • Red Hat Enterprise Linux 8
  • leapp upgrade
  • biosdevname

Issue

  • After upgrade the system from RHEL 7 to RHEL 8 using leapp the biosdevname scheme is ignored and the interfaces use the systemd scheme.
  • In RHEL 8 the biosdevname package is installed and the file /usr/lib/udev/rules.d/71-biosdevname.rules is present, however the rule is ignored.

Resolution

Add the parameter biosdevname=1 to the kernel command line.

# grubby --info=ALL | grep args
args="console=tty0 console=ttyS0,115200n8 no_timer_check crashkernel=auto $tuned_params"

# grubby --update-kernel=ALL --args="biosdevname=1"

# grubby --info=ALL | grep args
args="console=tty0 console=ttyS0,115200n8 no_timer_check crashkernel=auto biosdevname=1 $tuned_params"

# systemctl reboot

For more information on how to add the parameter check the article:

Root Cause

The rule in RHEL 7 force the system to use the biosdevname=1 even if it's not specified in the kernel command line: 

# cat /usr/lib/udev/rules.d/71-biosdevname.rules  | grep Dell
# whitelist all Dell systems
ATTR{[dmi/id]sys_vendor}=="Dell*", ENV{UDEV_BIOSDEVNAME}="1"

This line is not present in the RHEL 8 rule:

#  cat /usr/lib/udev/rules.d/71-biosdevname.rules  | grep Dell

For RHEL 8 and RHEL 9 running on Dell hardware the biosdevname=1 must be specified in the kernel command line.

Diagnostic Steps

The biosdevname package is installed and the file /usr/lib/udev/rules.d/71-biosdevname.rules is created correctly. The system does not show biosdevname=1 on the kernel command line.

# cat /proc/cmdline 
BOOT_IMAGE=(hd0,gpt3)/boot/vmlinuz-4.18.0-513.5.1.el8_9.x86_64 root=UUID=f7c93964-da54-4efa-8af3-f16616c286ad console=tty0 console=ttyS0,115200n8 no_timer_check crashkernel=auto

# rpm -qa | grep bios
biosdevname-0.7.3-2.el8.x86_64

# ll /usr/lib/udev/rules.d/ | grep biosdev
-rw-r--r--. 1 root root  995 Dec 18  2018 71-biosdevname.rules

However the rule/usr/lib/udev/rules.d/71-biosdevname.rules is ignored and interfaces are renamed using the systemd scheme.

# for i in eno3 eno4 eno1 ens2f0 ens2f1 ens7f0 ens7f1; do echo -n "$i : ";biosdevname -i $i; done
eno3 : em3
eno4 : em4
eno1 : em1
ens2f0 : p2p1
ens2f1 : p2p2
ens7f0 : p7p1
ens7f1 : p7p2

For information on how RHEL assigns network interface names using systemd's Predictable Network Interface naming scheme please check the documentation below:

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