Live migration between 2 defferent process host in fail over cluster

Live migration between different Intel Xeon generations in the same failover cluster is limited by CPU feature compatibility and side‑channel mitigation behavior.

From the described environment:

• Live migration works between hosts that share the same processor model.
• Live migration fails when moving between Xeon 6530P and Xeon Gold 6130, even with VM processor compatibility enabled.

Key points and actions based on the documented behavior:

1. Same CPU manufacturer is required, but not sufficient

• Live migration requires that all hosts use processors from the same manufacturer (Intel in this case), but differences in CPU feature sets and microcode/mitigation state can still block migration.
• VMM and Hyper‑V validate destination CPU capabilities before migration and will fail if required features are missing.

2. Processor compatibility mode is required when moving from newer to older CPUs

• When live migrating from a cluster with newer processors to a cluster with older processors, the VM processor must be configured to use the minimum feature set:
  • In PowerShell:

        Set-VMProcessor <VMName> -CompatibilityForMigrationEnabled $true
    

    or, in newer guidance, set CompatibilityForMigrationMode to MinimumFeatureSet.
  • In Windows Admin Center, select Compatible across other hosts with the same CPU manufacturer.
• After enabling this, the VM must be restarted so that it recalculates its capabilities based on the restricted feature set.

3. Side‑channel mitigations and microcode differences can still block migration

• When a VM boots on a host that exposes certain side‑channel mitigation features (for example, Spectre/Meltdown related), its guest OS may depend on those features.
• Migrating that running VM to a host whose microcode does not expose the same mitigation features is blocked to avoid exposing the VM to side‑channel attacks.
• Documented behavior:
  • Migration from a new system with side‑channel mitigation features to an old system without those features is prevented.
  • Recommended workaround at cluster level is to migrate VMs only from old microcode revisions to new ones, not the reverse.

4. Practical implications for the mixed 6530P / 6130 cluster

• If the 6530P nodes are “newer” in terms of CPU features/microcode and mitigation exposure, live migration from 6530P → 6130 may be blocked even with compatibility mode enabled.
• Supported patterns are:
  • Migrate from older CPUs (6130) to newer CPUs (6530P): VM capabilities are recalculated on restart and can use newer features.
  • Migrate from newer CPUs (6530P) to older CPUs (6130): requires minimum feature set compatibility and may still be blocked by mitigation differences.
• There is no documented setting that forces Hyper‑V to ignore these mitigation‑related incompatibilities; doing so would weaken security.

5. Recommended approach

• Ensure processor compatibility is correctly configured for each VM:
  1. In Hyper‑V Manager, open VM Settings → Processor → Processor Compatibility and enable compatibility across hosts with the same CPU manufacturer.
  2. Or run the PowerShell command above for each affected VM.
  3. Shut down and restart each VM once after enabling compatibility.
• Validate that all hosts are fully patched and running consistent firmware/BIOS and microcode where possible.
• For migrations that still fail from 6530P → 6130 after these steps, use only the supported direction:
  • Treat the 6130 nodes as “source/old” and 6530P nodes as “destination/new” and plan capacity so VMs normally move from 6130 → 6530P, not the reverse.
• If snapshots/checkpoints exist and a VM refuses to migrate due to processor differences, delete checkpoints and shut down the VM before attempting a cold move between hosts.

If strict bidirectional live migration between these two CPU generations is required, the only fully supported way is to standardize the cluster on a single CPU generation or on CPU models with matching feature/microcode exposure.

References:

• Troubleshoot live migration issues
• Configure processor compatibility mode in Hyper-V virtual machines
• Migration of virtual machines – overview
• Unable to migrate virtual machine from one host to another
• Troubleshooting guide: Hyper-V virtual machine live migration
• Use live migration with workgroup clusters