What you see
- A VM on Proxmox VE (2 disks, 13 GB) running a website and a counter written to disk 5 times a second, with fsync.
- In KoaVM: source scan, near-live mode, pre-flight checks, start.
- On the right, an outside probe hits the website every 0.2 seconds.
- Mirror copy while the VM runs: 248 seconds (sped up in the video). The website was unreachable for 9.7 seconds; the panel measured 14.1 seconds of downtime.
- At the end the counter is continuous: 9,435 writes, none lost. IP 10.88.0.61 and MAC unchanged.
The lab runs on nested nodes: on real servers times are lower. How it works step by step: Moving a VPS in 10 seconds and the migration guide.