LiveMigration between 2 clusters with different CVS

Question

Hello, we are trying to move Non-Prod VMs from clus1 to clus2 with different CVS its any way to do this without any downtime?

Answer 1

Hi Ramon Valdez.

Thank you for giving your question to us.

When clusters do not share the same physical storage (LUNs) or CSVs, you cannot perform a standard Live Migration. Instead, you must use a mechanism that migrates both the active memory state and the virtual disk (VHDX) storage simultaneously over the network.

So these are my recommendations:

1. Using Failover Cluster Manager
   If you are managing the clusters directly, follow this logic:

Ensure the VM is not currently a clustered resource (or use the "Move" command within the cluster context).

In Hyper-V Manager, right-click the VM -> Move.

Select Move the virtual machine.

Specify the name of a node in clus2.

Select Move the virtual machine's data to a single location and point it to the CSV path on clus2 (e.g., C:\ClusterStorage\Volume1).

2. Using System Center Virtual Machine Manager

If your environment utilizes VMM, this is the most streamlined approach:

Right-click the VM -> Migrate Virtual Machine.

Select a host in the destination cluster (clus2).

VMM will automatically detect that storage must be moved and will select the Live transfer type.

If you find my answer useful, please mark it as the "Accepted Answer" so other members can find the solution easily. Your help in supporting the community is much appreciated!

Best regards,
Scott Nguyen

Answer 2

Yes, live migration between two clusters that use different CSVs is supported, but there are important constraints and behavior to be aware of.

Key points from the support matrix and guidance:

1. Live migration between clusters is supported
   • VMM supports live migration of VMs between nodes in different clusters.
   • Requirement: both source and destination must be Hyper‑V failover clusters with CSV enabled.
2. Storage location matters
   Live migration itself does not move the VM’s storage. The VM’s VHD/VHDX location must be accessible from the destination cluster, or you must combine VM and storage migration:
   • If the VM is on CSV in the source cluster, that CSV must also be available to the destination cluster for pure live migration. If the CSVs are different and not shared, you cannot do a pure compute-only live migration with zero downtime.
   • To move both VM and storage in one operation, use live VM and storage migration (live VSM) where supported. This allows moving the VM and its disks to storage visible only to the destination cluster.
3. Live migration limitations relevant to your case
   • Migration between clusters is only supported on hosts running in failover clusters, and CSV storage must be enabled in the cluster.
   • Live migration alone “doesn't migrate virtual machine storage”; if the destination CSV is different and not shared, storage migration (or live VSM) must be used.
4. Using VMM between clusters with different CSVs There are two main patterns:
   • With shared storage (same SMB 3.0 share)
     If both clusters can see the same SMB 3.0 share, you can:
     1. Place the VM’s configuration and VHDs on that SMB 3.0 share.
     2. Use VMM → Migrate Virtual Machine with transfer type Live to move between clusters with minimal downtime, since storage does not move.
   • With no shared infrastructure (different CSVs)
     When CSVs are different and not shared:
     1. Use two SMB 3.0 shares (one for source, one for destination).
     2. Fully synchronize the source and destination VHDs.
     3. Then initiate live migration (live VSM) so that VM and storage move together. During this, the VM temporarily loses HA status, but user‑visible downtime is minimized.
5. High availability status during cross‑cluster moves
   • When migrating a VM between clusters, the VM temporarily loses its high availability status. A host failure during this window will make the VM unavailable, even if the move itself is “live” from a guest perspective.

Summary for clus1 → clus2 with different CSVs:

• Pure live migration with unchanged storage and zero downtime is only possible if the same storage (CSV or SMB share) is visible from both clusters.
• If clus1 and clus2 use different, non‑shared CSVs, use live VM and storage migration (live VSM) via VMM with SMB 3.0 shares and pre‑synchronized disks. This minimizes downtime, but HA is briefly lost during the move.

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References:

• Migration of virtual machines – overview
• Run a live migration in the VMM fabric
• Live Migration Overview