Transitioning from Synology DSM to TrueNAS - Help requested on some aspects

[dan]

Here’s the simplest and clearest explanation I’ve seen of snapshots:

Snapshots defy math and logic. "THEY DON'T MAKE SENSE!"

Why ZFS “snapshots” don’t make sense A children’s book for dummies, by a dummy “I don’t really understand how snapshots work.” “Why doesn’t destroying my snapshot free up more space?” “How come these numbers don’t add up?” Does this sound like you? Stop thinking about ZFS, pools, datasets, blocks, and snapshots. You want to demystify snapshots? Think about trucks, boxes, and colored stickers. What this illustrative walkthrough is not: It’s not a technical explanat…