Hi Sanjay, talking from real-world experience, the challenge is mostly the different libvirtd version.
You can upgrade the hosts one by one from Ubuntu 22.04 to 24.04, but have to remember, as Andrija mentioned in his reply, you will very likely only be able to live-migrate VMs from Ubuntu 22.04 hypervisors -> Ubuntu 24.04 hypervisors, not the other way around. Another challenge we've been facing has been caused by a newer kernel supporting more cpu flags / performance counters on exactly the same CPU: https://github.com/apache/cloudstack/discussions/11714 This unfortunately prevented live-migrations even from older Hypervisors to newer Hypervisors. This required us to stop and start all VMs once. But luckily this happened only once so far. As Andrija mentioned - give it a try with one hypervisor and try the live migration from the older hypervisor to the newer hypervisor. If it works, i would safely keep the updated hosts in the same cluster and upgrade one by one. If it fails, consider your options of stopping and starting every VM in the same cluster or a new cluster - the result is the same. Best regards, Stephan > Sanjay Kumar <[email protected]> hat am 30.10.2026 09:16 MEZ geschrieben: > > > Hello! > > We are planing to patch/upgrade KVM Ubuntu OS 22.04 to Ubuntu 24.04 but I > gone through the official notes. > > *"The explicit constraint requiring all KVM hosts within a single cluster > to run the exact same operating system distribution version"* > > Currently running apache cloudstack on 4.22 with kvm ubuntu 22.04. is there > any consequence if we proceed with upgrade or install and add to same > cluster on ubuntu 24. > > > Any help would be appreciated ! > > Thank you
