What must be compatible before live-migrating a VM between dedicated hosts?
Live migration depends on compatible hypervisors, guest CPU features, storage access and network continuity. Some platforms can transfer guest disks; others require shared storage for the selected migration mode. A successful memory transfer alone does not prove that the application will remain reachable or that migration traffic was protected appropriately.
Before you start
- Authorised source and destination access and a platform-supported migration plan.
Instructions
1. Inventory the guest and source stack
For libvirt-managed guests, inspect the selected connection and guest. Compare the corresponding information on the intended destination through authorised access.
virsh --connect qemu:///system version
virsh --connect qemu:///system dominfo example-vm
virsh --connect qemu:///system domblklist example-vm --detailsReplace example-vm with the verified guest. Record CPU configuration, storage sources and devices such as passthrough hardware that can constrain migration.
2. Validate the end-to-end migration design
Confirm destination capacity, compatible CPU exposure, storage ownership/locking, guest bridge or VLAN continuity and a supported transport. Migration may use separate data connections; an SSH management connection does not automatically encrypt every transport mode.
3. Define acceptance and recovery checks
Measure available bandwidth and workload write rate, set a permitted interruption window, and test the supported process with a representative noncritical guest before scheduling production movement.
Check the result
- The destination runs the intended guest with correct storage ownership and network identity, and application checks confirm acceptable interruption and data consistency.
Troubleshooting
- Migration cannot converge
- A high memory dirtying rate or limited network throughput may prevent completion; use the platform’s supported mitigation plan.
- The guest runs but is unreachable
- Check destination networking and provider MAC/IP rules.
- A device blocks migration
- Review device-specific support; do not detach a required device as an improvised workaround.
Official references
Use the documentation for your installed version when a flag, service name or platform feature differs.