Description of problem: Taking this from https://bugzilla.redhat.com/show_bug.cgi?id=1820140#c7 , when on hosted-engine environment customer tries to add more RAM than available on host, to HE-VM using memory-hotplug, he receives unclear and confusing error message " Operation Canceled Error while executing action: HostedEngine: Cannot edit VM. Memory size (32768MB) cannot exceed the minimal memory size of Hosted Engine hosts (31985MB)." In HE-environment might be some ha-hosts with less RAM than on the others, but the issue here is that customer is trying to add more RAM than available on current ha-host and he sees this error, which isn't much clear. What is minimal memory size of Hosted Engine hosts (31985MB)? Where does this value comes from? Version-Release number of selected component (if applicable): Software Version:4.4.1.7-0.3.el8ev. ovirt-hosted-engine-ha-2.4.4-1.el8ev.noarch ovirt-hosted-engine-setup-2.4.5-1.el8ev.noarch Linux 4.18.0-193.12.1.el8_2.x86_64 #1 SMP Thu Jul 2 15:48:14 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux Red Hat Enterprise Linux release 8.2 (Ootpa) How reproducible: 100% Steps to Reproduce: 1.Deploy HE over 2 ha-hosts with different ammount of RAM. 2.Try adding more RAM, than available on ha-host running the engine, to HE-VM using memory-hotplug. Actual results: Error message is unclear. Expected results: Error should be more specific and informative.
(In reply to Nikolai Sednev from comment #0) > Expected results: > Error should be more specific and informative. How would you suggest to improve it?
The message seems fine, the solution can be adding say tool tips and / or guided help in order to provide more detailed information.
(In reply to Arik from comment #1) > (In reply to Nikolai Sednev from comment #0) > > Expected results: > > Error should be more specific and informative. > > How would you suggest to improve it? I would suggest to check on which host the VM is actively running and then: 1.If customer is trying to add more RAM than available on host, then to print something like "You're not allowed to add more memory to HE-VM, than available on host." 2.If customer is trying to add more memory than the slowest host in cluster can support, then print something like "You're not allowed to add more than (amount of RAM on slowest host in cluster) to be able to run HE-VM on all ha-hoists in cluster". There are two cases and they have to be handled separately and messages should be clear.
We wouldn't want to have two different cases when (2) includes (1) - if you set the memory to be higher than the physical memory of the host the HE VM runs on, you necessarily exceeded the physical memory of the minimal HE host. I see your point about second message though - you prefer to be provided with the motivation for the check rather than what the check actually does. In this case though the motivation, in my opinion, it quite clear and it's better to be more explicit about what caused the failure.
(In reply to Arik from comment #4) > We wouldn't want to have two different cases when (2) includes (1) - if you > set the memory to be higher than the physical memory of the host the HE VM > runs on, you necessarily exceeded the physical memory of the minimal HE host. > I see your point about second message though - you prefer to be provided > with the motivation for the check rather than what the check actually does. > In this case though the motivation, in my opinion, it quite clear and it's > better to be more explicit about what caused the failure. People who don't know how the code works inside, won't understand current error. IMHO we should refine the message and supply some documentation or pop-up explanation message.
I wouldn't be so definite about it - people can understand that without knowing how it's implemented. With no alternative that clearly improves it, keeping it as is.