How to disable NetworkManager in RHEL 8 ?

環境

Red Hat Enterprise Linux (RHEL) 8

問題

What steps are needed to disable the NetworkManager service?

決議

At first, please note that the old 

networks-scripts

 have been deprecated and are not the defaults anymore.

• ifup

   belongs to the 

  NetworkManager

   package by default.

  Raw

  # readlink $(which ifup)
  /etc/alternatives/ifup
  
  # readlink $(readlink $(which ifup))
  /usr/libexec/nm-ifup
             

• You can change this behaviour by installing the package below. After that, the ifcfg configurations will be handled by the 

  network.service

  Raw

  # yum install network-scripts
  
  # readlink $(readlink $(which ifup))
  /etc/sysconfig/network-scripts/ifup
             

• Be aware that you'll get a warning on deprecation:

  Raw

  # ifup ens3
  WARN      : [ifup] You are using 'ifup' script provided by 'network-scripts', which are now deprecated.
  WARN      : [ifup] 'network-scripts' will be removed in one of the next major releases of RHEL.
  WARN      : [ifup] It is advised to switch to 'NetworkManager' instead - it provides 'ifup/ifdown' scripts as well.
             

• If you are annoyed by this warning, you can disable them at your own risk:

  Raw

  # touch /etc/sysconfig/disable-deprecation-warnings
             

• After that, you should be able to do the same configuration as on your RHEL 7:
  • Stop and disable the NetworkManager
  Raw

  # systemctl stop NetworkManager
  # systemctl disable NetworkManager
             

  • Add the 

    NM_CONTROLLED="no"

     parameter to your 

    /etc/sysconfig/network-scripts/ifcfg-<DEV>

     files to ensure that NetworkManager won't handle your device, where 

    <DEV>

     is your network interface card (e.g. eth0, ens3, enp2s0f0, ...).
  • Use the 

    network.service

     instead of 

    NetworkManager.service

    . For example:
  Raw

  # systemctl status network