I’m been trying to figure out why the configuration with RF2 & N+1 reserves more capacity than just RF2. I understand that with RF2 all the data is duplicated along the cluster and the failure of one node is tolerated. In my scenario I have a 3-node cluster with 34TiB of effective capacity, so with RF2, I would have only 17TiB, everything is clear until that point.
But the extent store assuming RF2 & N+1 gives me 11.3TiB, which is 1/3 of my available capacity. So...the question is: If I reserve capacity, by tripling all the data, that is for tolerate 1 additional node failure besides the 1st one (tolerated by RF2)?
A silly conclussion would be that with RF2 & N+1 the cluster is able to tolerate 2 nodes and continue operating just with one node, but I know that is not posible.
So, why assuming RF2 & N+1 reserves more TiB’s than just RF2? Please, I would appreciate the help.
Thanks in advanced!
Best answer by AlonaView original