I experienced this limitation, too. I am speaking about the Mgmt ISO of R80.20 - It seems, that the installer/grub-install is still not able to work with disks bigger than 2TB
I my case I decreased the virtual disk to 1,99 TB and installation worked.
If you still want to have a have diskspace more then 2 TB in this VM with there a two options:
- Install with 1,99 TB and then add a 2nd disk and add it with LVM commands ( pvcreate, vgextend und lvextend)
( I never used the tool, that Checkpoint is providing ("lvm_manager") - it is not flexible enough )
This will definitly works !
-) Increase the size of the existing disk to the size you want - but only after installing with sizce below 2 TB and extend this disk with LVM commands ( maybe "lvm_manager" do the job here)