Tip of the Day: Understanding KVP in Hyper-V

Today’s Tip…

While not new, some people have confusion about how the Hyper-V host communicates simple string data with the VM.

This is part of the Integration Services, specifically Data Exchange.

<VM Properties as seen from the host>

<Services within the VM>

NOTE:  Do not mix this up with Guest Services, which allow files to be passed between host and VM.

The data exchange is done via a Key-Value Pair (KVP).

This data is passed to Windows based VMs by writing to the VM’s registry.

For Linux based VMs, a daemon process named hv_kvp_daemon is utilized.  The data is saved directly to the Linux file system.

NOTE:  Information about the host is updated if the VM is migrated to a different host.