Treat Hyper-V key-value exchange as persistent host-visible metadata

Source facts

Hyper-V Data Exchange shares small pieces of information between a guest VM and its host, including automatically generated and custom key-value pairs. Keys and values are strings. The information travels over VMbus without requiring a network connection between host and guest. Pairs persist until deleted and travel with the VM during live migration. Microsoft tells applications to remove pairs that are no longer needed. Microsoft documentation.

Applicability

Identify the producer, consumer, data contents, and lifecycle of each proposed key. Review whether the integration service and guest implementation required by the application are present in the supported configuration.

DSE recommendation

Create a small metadata contract naming each key, its meaning, its owner, and when it should be updated or removed. Avoid placing credentials or unnecessary sensitive data in the contract. Define how consumers should handle a missing or stale value and who will investigate conflicting entries.

Verification

Create and read a non-sensitive test pair from the intended endpoints, change it, and confirm deletion when the task finishes. Include a controlled VM migration if the application relies on migration continuity. Record the actual values and timing observed rather than interpreting a stale pair as current guest health.

Official references

Microsoft Learn: Data Exchange: Using key-value pairs to share information between the host and guest on Hyper-V. Source reviewed September 8, 2026.