Preventing Duplicate machine-id When Cloning RHEL Virtual Machines

overview when cloning red hat enterprise linux virtual machines on vmware, the system file /etc/machine id is sometimes cloned along with the os this results in multiple hosts sharing the same machine identity, which is unsupported and can cause issues with system services, security tooling, and kubernetes this article explains why this happens and how to correctly remediate and prevent it what is machine id /etc/machine id is a unique identifier generated by systemd for each operating system instance it is used by • systemd and journald • networking and d bus services • endpoint security agents such as trellix • inventory, monitoring, and licensing systems • kubernetes node identity and stability each rhel vm must have a unique machine id why duplicate machine id is a problem if multiple vms share the same machine id, the following issues may occur • security agents may overwrite or conflict with each other in management consoles such as trellix epo • kubernetes nodes may behave unpredictably or fail to register correctly • logs may collide or be misattributed • host identity in monitoring and inventory systems may be incorrect • systemd based services may malfunction this configuration is unsupported and should be corrected immediately how to fix an already cloned vm perform the following steps on each cloned vm remove the existing machine id files sudo rm f /etc/machine id sudo rm f /var/lib/dbus/machine id regenerate a new machine id sudo systemd machine id setup reboot the system sudo reboot verify uniqueness cat /etc/machine id ensure each vm reports a different value important note for kubernetes or trellix managed systems if the system is already • registered in trellix epo • joined to a kubernetes cluster it is recommended to • remove or drain the node from kubernetes • regenerate the machine id • reboot • rejoin the kubernetes cluster • re register the trellix agent this prevents identity conflicts across platforms preventing the issue in future clones when creating golden images or vm templates • remove /etc/machine id before converting the vm to a template • do not clone powered on vms • allow systemd to generate a new machine id on first boot • use cloud init or first boot scripts when available this ensures each vm receives a unique identity automatically summary cloning rhel vms with an existing machine id causes duplicate host identities and can lead to operational and security issues regenerating the machine id after cloning and following proper template hygiene prevents these problems and is required for stable kubernetes and endpoint security operation