Update the shell welcome message for RHV host when the user ssh in to warn not to run `yum update` if the host is not in maintenance, since it can cause the VMs running on the host to dysfunction. This is something that we can do at vdsm level, in vdsm rpm postinstall scripts, for instance, without impacting core OS components. This still won't prevent the user from running the update command without host maintenance in the engine, but it will reduce the probability of this to happen. And this seem to be relatively easy to implement as opposed to try figuring out if the host is in maintenance and preventing the yum command to run. How to do it? For exmaple, using /etc/motd: https://access.redhat.com/solutions/223483 Suggested words to use: "Ensure host is in maintenance before running `yum update`. Otherwise it can cause VMs running on the host to dysfunction." But I would run this through a native english speaker first :)
IMO this should be handle within host deploy process, probably worth to add to ovirt-host-deploy ansible role. Targeting to 4.3, when done let's discuss backports
Ideally would be to have some flag set on the host and lock the yum process from updating somehow as long as the host is not in maintenance. But this probably would be much harder to implement.
Closing old RFEs. If still needed, please re-open and provide a business justification.