System Disks usage

I have installed OpenNebula, and imported VM’s from vcenter. That works perfectly.

Then i tried to look at using quotas where vcpu and memory is counted just fine from imported VM’s.

However System Disks are not counted at all, so all vm’s are reported with 0kb system disk.

Are there any wise men who can point me in the right direction?

I am using vCenter / ESXi 6.7 update 2.

best regards.