Hyper-V VMs not showing up after adding host asset

SUMMARY

After a Hyper-V Node or CLuster is added in the COnfugure Protected Assets tab, Hyper-V VMs managed under that asset may not appear in some cases.

ISSUE

After adding a Hyper-V Host object under the Configure > Protected Assets tab, you may notice VMs do not appear under that asset that shoudl be present.  This article cooalates several issues that could cause this behavior. 

RESOLUTION

1) Ensure Hyper-V PowerShell Management tools are installed on all hyper-V nodes.   For existing deployments, powershell tools may also have been removed or broken by updates post Unitrends deployment which could result in backup issues specifically stating PowerShell Tools are missing.  

For HV 2012 and 2016 see one of the following:
Hyper-V Backups fail getting version of the VM or because powershell tools are missing
For HV 2008R2 instead:
Hyper-V backup fails with error 'Hyper-V PowerShell Module is not installed'

2) If your environment includes a Hyper-V Cluster ensure you have first added each node in the cluster seperately as assets, then, add the cluster resource object as an additional; host.  The cluster must have it;s own unique DNS name and static IP.   Each node must have a DNS name and accessible IP for backup.  IP-Less clusters are not supportable for VM-level backups.  

3) if using SMB3 storage with Hyper-V, ensure you have followed the SMB 3.0 requirements noted in the "Additional Hyper-V Requirements" section of the admin guide.

4) For a VM to appear managed by a cluster, it must both be in HA configuration and reside in a CSV.  VMs in HA that reside in standalone storage are improperly configured per Microsoft documentation as are VMs that reside in cluster storage that are not cluster managed.  Those environmental issues must be resolved before the VM can pr protected.  

5) (rare) VM dependencies for cluster storage may need to be reviewed.  This typically affects 2008R2 hosts, but similar steps could also apply from the following KB to other systems as well. Hyper-V cluster Nodes, not showing all the Hyper-V guest systems

CAUSE

Itemization of guests for backup inventory depends on powershell functionality, proper cluster architecture, and proper guest registration and configuration in the host.  Hyper-V Cluster architecture and Type-2 hypervisor architecture are unfortunately more complicated and more limited vs Type-1 systems like VMWare.  Unitrends in some cases will fail to retrieve inventory from Hyper-V, but in other cases will de-list VMs from our inventory that cannot be protected via specific registered assets due to environmental configurations.  

NOTES

Additional Hyper-V Concerns: 

Ensure that for any given CSV, all guests running active in that CSV are owned by a single host.  Hyper-V itself is active-active, meaning that multiple hosts in a cluster can be concurrently running different VMs, but, CSVs and VSS technology used to snapshot disks is active-passive.  If guests from different hosts reside in the same CSV at the same time substantial unnecessary load will be placed on the host and on live migration and CSV network segments during any VSS operations.  This may result in backup failures, performance issues, loss of CBT data block tracking necessitating unplanned full backups to reset, or in cases where CSV networks are strained may result in Hyper-V disconnecting the CSV resources resulting in production VM crash and potentially data loss.  This configuration is not supported by Microsoft as a production state, but is only to be used temporarily in transitional states.  Please always ensure Microsoft Best Practices are followed and best practice analyzer reviewed for hyper-V hosts for storage, resource, and network creation.  

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