Tablo rec_ids, when does the number roll? What is the max rec_id?

I’m talking about the lower levels of Tablo, in particular the rec_ids… I figure these do rollover eventually, but wondered how all of that is handled and what the max is?  Let’s say the max is 10 (it’s not 10 thouigh, just an example).  And let’s say it does rollover, so the next rec_id is 0.  What if there’s already something at 0?

So… I’m curious about the max rec_id value… and what happens when it rolls over and how Tablo handles the conflict (does it just keep incrementing until it finds an opening?)