Cool, thanks. But, there's nothing I really need to calculate, but good to know it exists. But, still curious if one double-partitioned physical drive can participate in both a RAID config as well as appear as another simple data storage drive.
If the calculator does indeed answer my question, then the language is a bit ambiguous, as it states I would have 1 TB of "unused space". Does "unused space" mean that space that just is not available as a simple storage drive partition, or does it mean simply that the 1 TB would not participate in the RAID?
EDIT: Synology footnote as follows: 3.
When using SHR or SHR-2 HDD protection as your RAID type, the Unused space will be automatically reserved for future expansion. On the contrary, Unused space under other RAID types indicates the space that can't be utilized and is thus wasted.
It's hard to imagine, but according to the above footnote, a physical drive, even if partitioned, cannot participate in a RAID-1 config and be visible as a single storage drive simultaneously. The language used for SHR is a bit unclear. Anyone know?