Redundancy of Raid 10 with a hot spare?

Raid 10 has a 2N redundancy. What is the redundancy for Raid 10 with a hot spare?

Am I correct in thinking it is 2N+1 redundancy?

Am I correct in thinking it is 2N+1 redundancy?

No, why would it? Consider thinking about edge cases.

Redundancy is 2N - data is stored on 2 discs, able to handle a failure.

What in your world does a hot spare - that takes HOURS TO INITIALIZE - actually change? Here is a hint: NOTHING. If one drive fails, there is no redundancy - UNTIL THE HOT SPARE HAS INITIALIZED. Which, again, can take hours.

I once had a Raid 6 failing while I watched it. Within like 5 minutes 3 discs went out. 2 Hot spares changed NOTHING - nada. Exactly this scenario you describe.

Your failure: assuming a hot spare does not take time to initialize.