Data VDEV is bigger than drive size?

[winnielinnie]

@ericloewe, feel free to steal this as well, which goes the extra mile with pretty pictures!

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…