Duplicate UUIDs when VMs are deployed from vApp templates in vCloud Director
As mentioned in this VMware KB article when VMs are created using vApp template or OVF using vCloud Director, they will share the same BIOS UUID by default.
VirtuCache has restricted support for vCenters that contain VMs that share the same BIOS UUIDs.
- Only Write-Through caching policy can be applied to such VMs, Write-Back caching policy cannot be applied.
- VirtuCache GUI might not list these VMs. This issue will be fixed by Virtunet on a case-by-case basis (depending on how the VMs with duplicate UUIDs were created). Even if these VMs are not displayed in the VirtuCache GUI, they will be listed using VirtuCache CLI (vnxcli). You can go to ESXi CLI > type vnxcli > type list-vms to see all the VMs on the host and their caching status (including VMs that share the same UUID).
For such VMs that were provisioned using vCloud Director using vApp template or OVF, the only way to make Write-Back policy work for these VMs and for these VMs to show in the VirtuCache GUI, is to change the system configuration value named CloneBiosUuidOnVmCopy in vCloud Director to 0 from the default value of 1. The value of 0 for CloneBiosUuidOnVmCopy will generate a new BIOS UUID for each VM provisioned using vCloud Director. Subsequently, such VMs that have a unique BIOS UUID will be displayed in the VirtuCache GUI and Write-Back caching policy can also be applied to them. For further details on how to make this change in vCloud Director, please refer to the VMware KB article listed above.