Can you tell me about reliability/redundancy?

What happens if the node that has my files goes offline forever? Will i lose my files or are there other copies of them in the network ?

I don't pretend that SIA duplicates my uploaded file to every node of the network, that would be unsustainable, but at least i want to know how many
 redundant copies are there.

That is important because , unlikely Onedrive/Gdrive etc.,  a P2P network like SIA has poor uptime for each node, i.e. each node is not always online and there's no guarantee that it will keep working with SIA forever , while Onedrive servers have 99.9% uptime and will be there forever.
So i think that some redundancy is needed for a P2P cloud storage, i just want to know if SIA has it.

I would pay more than 2$/month but i want to be sure that i won't lose my files.