Hyper-V Integration Services

Integration services (often called integration components), are services that allow the virtual machine to communicate with the Hyper-V host. Many of these services are conveniences while others can be quite important to the virtual machine's ability to function correctly.

This article is a reference for each integration service available in Windows. It will also act as a starting point for any information related to specific integration services or their history.

User Guides:

Quick Reference

Name Windows Service Name Linux Daemon Name Description Impact on VM when disabled
Hyper-V Heartbeat Service vmicheartbeat hv_utils Reports that the virtual machine is running correctly. Varies
Hyper-V Guest Shutdown Service vmicshutdown hv_utils Allows the host to trigger virtual machines shutdown. High
Hyper-V Time Synchronization Service vmictimesync hv_utils Synchronizes the virtual machine's clock with the host computer's clock. High
Hyper-V Data Exchange Service (KVP) vmickvpexchange hv_kvp_daemon Provides a way to exchange basic metadata b etween the virtual machine and the host. Medium
Hyper-V Volume Shadow Copy Requestor vmicvss hv_vss_daemon Allows Volume Shadow Copy Service to back up the virtual machine with out shutting it down. Varies
Hyper-V Guest Service Interface vmicguestinterface hv_fcopy_daemon Provides an interface for the Hyper-V host to copy files to or from the virtual machine. Low
Hyper-V PowerShell Direct Service vmicvmsession not available Provides a way to manage virtual machine with PowerShell without a network connection. Low

Hyper-V Heartbeat Service

Windows Service Name: vmicheartbeat
Linux Daemon Name: hv_utils
Description: Tells the Hyper-V host that the virtual machine has an operating system installed and that it booted correctly.
Added In: Windows Server 2012, Windows 8
Impact: When disabled, the virtual machine can't report that the operating system inside of the virtual machine is operating correctly. This may impact some kinds of monitoring and host-side diagnostics.

The heartbeat service makes it possible to answer basic questions like "did the virtual machine boot?".

When Hyper-V reports that a virtual machine state is "running" (see the example below), it means Hyper-V set aside resources for a virtual machine; it does not mean that there is an operating system installed or functioning. This is where heartbeat becomes useful. The heartbeat service tells Hyper-V that the operating system inside the virtual machine has booted.

Check heartbeat with PowerShell

Run Get-VM as Administrator to see a virtual machine's heartbeat:

Get-VM -VMName $VMName | select Name, State, Status

Your output should look something like this:

Name    State    Status
----    -----    ------
DemoVM  Running  Operating normally

The Status field is determined by the heartbeat service.

Hyper-V Guest Shutdown Service

Windows Service Name: vmicshutdown
Linux Daemon Name: hv_utils
Description: Allows the Hyper-V host to request that the virtual machine shutdown. The host can always force the virtual machine to turn off, but that is like flipping the power switch as opposed to selecting shutdown.
Added In: Windows Server 2012, Windows 8
Impact: High Impact When disabled, the host can't trigger a friendly shutdown inside the virtual machine. All shutdowns will be a hard power-off, which could cause data loss or data corruption.

Hyper-V Time Synchronization Service

Windows Service Name: vmictimesync
Linux Daemon Name: hv_utils
Description: Synchronizes the virtual machine's system clock with the system clock of the physical computer.
Added In: Windows Server 2012, Windows 8
Impact: High Impact When disabled, the virtual machine's clock will drift erratically.

Hyper-V Data Exchange Service (KVP)

Windows Service Name: vmickvpexchange
Linux Daemon Name: hv_kvp_daemon
Description: Provides a mechanism to exchange basic metadata between the virtual machine and the host.
Added In: Windows Server 2012, Windows 8
Impact: When disabled, virtual machines running Windows 8 or Windows Server 2012 or earlier will not receive updates to Hyper-V integration services. Disabling data exchange may also impact some kinds of monitoring and host-side diagnostics.

The data exchange service (sometimes called KVP) shares small amounts of machine information between virtual machine and the Hyper-V host using key-value pairs (KVP) through the Windows registry. The same mechanism can also be used to share customized data between the virtual machine and the host.

Key-value pairs consist of a “key” and a “value”. Both the key and the value are strings, no other data types are supported. When a key-value pair is created or changed, it is visible to the guest and the host. The key-value pair information is transferred across the Hyper-V VMbus and does not require any kind of network connection between the guest and the Hyper-V host.

The data exchange service is a great tool for preserving information about the virtual machine -- for interactive data sharing or data transfer, use PowerShell Direct.

User Guides:

Hyper-V Volume Shadow Copy Requestor

Windows Service Name: vmicvss
Linux Daemon Name: hv_vss_daemon
Description: Allows Volume Shadow Copy Service to back up applications and data on the virtual machine.
Added In: Windows Server 2012, Windows 8
Impact: When disabled, the virtual machine can not be backed up while running (using VSS).

The Volume Shadow Copy Requestor integration service is required for Volume Shadow Copy Service (VSS). The Volume Shadow Copy Service (VSS) captures and copies images for backup on running systems, particularly servers, without unduly degrading the performance and stability of the services they provide. This integration service makes that possible by coordinating the virtual machine's workloads with the host's backup process.

Read more about Volume Shadow Copy here.

Hyper-V Guest Service Interface

Windows Service Name: vmicguestinterface
Linux Daemon Name: hv_fcopy_daemon
Description: Provides an interface for the Hyper-V host to bidirectionally copy files to or from the virtual machine.
Added In: Windows Server 2012 R2, Windows 8.1
Impact: When disabled, the host can not copy files to and from the guest using Copy-VMFile. Read more about the Copy-VMFile cmdlet.

Notes:
Disabled by default. See PowerShell Direct using Copy-Item.

Hyper-V PowerShell Direct Service

Windows Service Name: vmicvmsession
Linux Daemon Name: n/a
Description: Provides a mechanism to manage virtual machine with PowerShell via VM session without a virtual network.
Added In: Windows Server TP3, Windows 10
Impact: Disabling this service prevents the host from being able to connect to the virtual machine with PowerShell Direct.

Notes:
The service name was originally was Hyper-V VM Session Service.
PowerShell Direct is under active development and only available on Windows 10/Windows Server Technical Preview 3 or later hosts/guests.

PowerShell Direct allows PowerShell management inside a virtual machine from the Hyper-V host regardless of any network configuration or remote management settings on either the Hyper-V host or the virtual machine. This makes it easier for Hyper-V Administrators to automate and script management and configuration tasks.

Read more about PowerShell Direct.

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