One of the nodes in our 4-node minio cluster is having issues and will be terminated by our cloud provider in a couple of weeks. I have done prior testing with minio and know that it will continue to function with 3 nodes, but I will be bootstrapping a new node a few minutes after I terminate the old one, and our container orchestrator should drop a new minio container on that node and into the minio cluster; I'm not concerned about that part.
What I would like to know is how can I kickstart minio to rebalance after the new node is online? In the past when I tested this scenario the new minio container did not pull much if any data from the other nodes. Is that because we're still at the (n/2) + 1?
Hypothetically, what would it take for me to see data being transferred between minio containers-- another (different) node being replaced after the new one is online?
At what point would I see data loss?
If it matters, this minio registry just holds container images from an internal docker registry-- the amount of data it holds is relatively small and static, and writes only happen when I push an image to the registry.
FWIW, minio does not resync automatically. You need to do an "mc admin heal ". Even that sppears to only get the added minio container's disk into the online state, so it is available for subsequent uploads.