Symptoms
After upgrading vCenter to 6.7 or 7.0, instant clone deployment fails with following error in the Activity log of Admission Console.SERVER_FAULT_FATAL - Runtime error: No full links for internal VMs found.You can find NGVC.log on Resource Manager.==========2022-09-14 15:50:30,259 DEBUG [com.vmware.daas.cloneprep.cache.CacheManager]-[CacheRefreshThread-https:(vCenter FQDN)/sdk] VC Version: VC Version: 7.0.2, API Version: 0.0:2022-09-14 15:50:31,122 WARN [com.vmware.daas.cloneprep.cache.ObjectStore]-[CacheRefreshThread-https:(vCenter FQDN)/sdk] Host: host-xxxxx not available for provisioning. ConnectionState=connected, PowerState=poweredOn, MaintenanceMode=false, AdminRequestedMaintenance=0, MarkedAsFailed=false, Host Version: 6.5.0, Host API Version: 6.5==========
Cause
This issue occurs because of an internal design incompatibility when mixed versions of ESXi and vCenter Server are used,vSphere 6.7 has a new API for instant clones. Therefore, if you are using instant clones, and are upgrading from a vSphere version earlier than 6.7 to vSphere 6.7 or later, this issue is occurred.For example, if you are upgrading from vSphere 6.0 to vSphere 6.7, from vSphere 6.5 to vSphere 6.7, or from vSphere 6.5 to vSphere 7.0, this issue is occurred.This issue is not occurred if you are upgrading from vSphere 6.7 to vSphere 7.0.
Resolution
For Instant Clone feature to function properly, its required to keep the versions of ESXi hosts and vCenter server under same versions.Currently, instant clone works when the versions of ESXi and vCenter Server are the same. (i.e. ESXi 6.5 with vCenter Server 6.5 or ESXi 6.7 with vCenter Server 6.7 is used) Hence, to resolve this issue, upgrade the ESXi hosts to 6.7 as well.During upgrade vSphere, you need to take maintenance time with below procedure.1. Take an Assignment Offline the instant clone.2. Upgrade ESXi host.3. Bring an Assignment Online the instant clone.Take an Assignment Offline or Bring an Assignment Online
Related Information
This issue depends on Instant Clone Smart Provisioning.If it is the provisioning mode A, this issue is occurred.On the other hands, if it is the provisioning mode B, this issue is not occurred.This issue is not only Horizon DaaS, but also Horizon has same issue.Upgrade Instant-Clone Desktop Pools When You Upgrade vCenter Server to vSphere 6.7 or Later
