I'm currently in the process of moving an Elasticsearch cluster from VM/SAN to physical/local disk.
Current cluster is 6 VMs, each with 2 data nodes and either a master or client node (total 3 master, 3 client, 12 data). Index shards/replicas are 6/1.
New cluster is 4 physicals, each with 7 data nodes, 1 master and 1 client (total 4 master, 4 client, 28 data), same 6/1 shard/replica.
Both clusters will be 7.1.1
When I look around for migration methods, I see things like logstash (did it this way last time, since I wanted to do some processing on the way over), or snapshots, etc.
My question is, can I not just add all the new nodes into the cluster, let it re-organize/stabilize, switch the load balancer to point to the new client nodes, then start removing the old nodes? I never see this offered as a migration solution, so I keep thinking there must be a reason why.