SSDs are very likely to put all those copies into a single physical block underneath. Since ZFS makes backups easy, better stick to copies=1 and do backups often.
I shouldn't think that's true. Why wouldn't the firmware be splitting writes across different physical chips for performance and wear leveling reasons?
What do you mean? The discussion in this particular sub-thread is about running ZFS on a single drive (think laptop). Does it have some kind of mechanism to send the write for a copy "later enough" that it will likely end on a different physical block?
I meant "primarily this copies mechanism is targeted towards multiple devices setup".
With a single SSD it's indeed prone to the caveat which was pointed out; even if not due to being mapped to same storage "area" but also because SSDs often fail completely.
Also makes sense to note that __when__ narrowed to a single-disk setup ZFS' can be interchanged with Btrfs; almost same set of features but lesser overhead and complexity.