Comment 3 for bug 1892367

> But, in our case, if we are not doing a zipl or update-initramfs -u, the value is not getting modified.

Ubuntu initramfs copies all udev rules that are present in /etc/udev/rules.d into the initramfs. It cannot possibly know which ones are hand-edited, which ones are generated by zdev, and which ones must be in the initramfs or not. For example, we do support bringing up networking interactively inside the initrd, thus even the qeth ones are useful in the initrd.

Separately, we do ship zdev & initramfs integration hook (/lib/s390-tools/zdev-root-update) and thus zdev itself knows how to update the initramfs.

We have discussed this before that `chzdev` persistent enable|disable commands should always invoke zdev-root-update, but that has not been implemented upstream. I too find it confusing that chzdev enable|disable doesn't call zdev-root-update hook (which in turn calls update-initramfs -u to update udev rules in the initrd).

Please open issue against upstream chzdev https://github.com/ibm-s390-tools/s390-tools to call zdev-root-update hook upon any persistent changes to zdev devices.