We have a distributed clustered environment and need to upgrade it to the latest version. The plan is to install the latest version on a new set of physical servers. How do we migrate the old data from the existing infrastructure (3 indexer cluster) to the new 4 indexer cluster.
If you can, your easiest solution would be run both clusters in parallel and utilize hybrid / distributed search to search the new and old clusters. Once your data is aged out, you can decommission the old clusters.
Another option would be to bring the new members into the cluster, up the REP factor and Search factor to balance across to the new members. Then decommission the older servers from the cluster..