Hi, everything seems correct to me. If you do a hard disk calculation in TRAID you should find your final values with the formatted hard disks.
From the Terramaster website you can calculate your TRAID directly: https://support.terra-master.com/raidca ... n/?lang=en
Have you modified the volume size in control panel? Extra capacity in Storage Pool could either be used to expand existing volumes or to create additional volumes, on the same pool, for different purposes.