I read that consensus algorithms allow you to ensure the atomic commit. That is, in order to save a large amount of data on the disk, as if it is a single object, the article advises a consensus protocol.
I could not understand what consensus has to do with your writing on disk, where you seem to have only a single node writing a contigous piece of information (I asked this Q at dba but they blocked my account saying that it is a violation) but, anyway, let's take a distributed DB. I read that consensus allows me to agree upon a single value (without resorting to any locks). But, atomicity means that you should agree upon many values at the same time. How do you exploit the consensus algorithms for updating multiple values atomically?
I see in computerphile about Paxos that you can use consensus to take locks. Do you use consensus just to take them and commit a transaction under the locks?