I’ve uploaded a half dozen or so Windows VMs (mostly Server 2012 R2) using the upload feature of Workstation Pro 15 to ESXi 6.5. In every case the source vmdk is 24 GB, but the VM on ESXi ends up at 100 GB. There are no snapshots. What am I doing wrong?
I assume that you used a sparse vmdk format on Workstation with a nominal size of 100gb.
If you want to convert the Workstation format to a thin provisioned ESXi format use a tool that gives you full control over the output format.
You could do this by uploading the VMDK via WinSCP and then convert it via
vmkfstools -i uploaded-ws.vmdk thin-esxi.vmdk -d thin