Left over MRT RCT files

[Perry]

Some of my virtual machines have left over MRT and RCT files next to the .VHD files with the same name created by Veeam (I suppose) during the backup process. But other VMs backed up with the same job do not. Is this just left over garbage I can delete? Maybe left over from a canceled backup?

[PTide]

Hi,

RCT and MRT files are related to Hyper-V 2016 native change tracking mechanism. Possible reason why you see the files only for some VMs is that the VMs do not meet RCT requirements (VM configuration version is upgraded to 8 ).

Thanks

[Perry]

But Hyper-V on 2016 host does change tracking natively so why does Veeam create its own RCT and MRT files for each VM during backup instead of using the ones Hyper-V created? It would seem that creating Veeam's own RCT and MRT files would take longer since it has to scan the entire VHD to create them.