The following is a quick write-up about the function of Hyper-V Integration Services (HIS). The idea is to give IT admins a quick overview:
1. You need to update Hyper-V Integration Services (HIS) inside each VM whenever you run Windows Update on the host
Read this post: It’s not automatic!
2. Without up-to-date HIS the VM won’t function properly.
That’s because the host relies on communication protocols from the client. The host doesn’t always emulate every hardware bit correctly when the VM speaks ‘an old language’.
3. You need to install HIS inside each VM to get best performance
All hardware drives needed for proper emulation are part of the Hyper-V Integration Services. If you don’t install them, the VM and/or host may have to revert to legacy built-in drivers. In addition many timing related functions and hardware access functions depend on up-to-date integration drivers.
4. If HIS aren’t up to date, it will break your backups
VM live backup is a very complex process involving host and VM. There’s a good deal of communication occurring when a backup is triggered. If integration services aren’t the latest, it can happen that Hyper-V pulls the VM into a saved state.
The decision to push a VM into Saved State is always made by the Hyper-V Management Service, not the backup application.
If that’s what’s happening to your VMs, have a look at:
this VSS Diagnostic Tool: http://backupchain.com/VssDiag.html
And this backup software for Hyper-V and Windows: http://backupchain.com/Hyper-V-Backup.html