Episode 24 of the InventiveHQ KVM virtualization series.
Lab verified July 2026 · Ubuntu 26.04 · libvirt 12.0.0 · QEMU 10.2.1
What this episode proves
- Configure outer-hypervisor power control for each nested HA node
- Isolate the active node
- Prove fencing completes before guest restart
- Test quorum loss and show that unsafe restart is refused
Validated workflow
1. Configure outer-hypervisor power control for each nested HA node
fence_virsh --plug=kvm-ha03 --action=status
2. Isolate the active node
pcs property set stonith-enabled=true
3. Prove fencing completes before guest restart
pcs stonith fence kvm-ha03
4. Test quorum loss and show that unsafe restart is refused
corosync-quorumtool -s
Finished state
Fencing is enabled, tested, and required; all three nodes are healthy and rejoined. The public scripts contain no private keys, passwords, or tokens. Review names, addresses, paths, ownership, backups, quorum, and fencing for your own environment before running them.