My cluster has manual snapshots taken every 30 minutes. The indicies are rotated monthly, and all similar indices are part of the same alias.
I'm planning on retiring some of the older indices.
This is probably a dumb question - Will the next time a snapshot runs after I delete the indices also delete them from the snapshot? That is, will I be able to restore deleted indices after newer snapshots are taken?
Is it safer for me to register a separate snapshot for the indices I'm deleting?
The next time you run a snapshot, it will have a unique name. In the repo metadata, it will have references to exactly the segments/shards/indices that were comprised the indices you named in your snapshot command. It will not remove anything from the repo.
The snapshots that you took previously will still have the references that they had when you took them, and the segments referred to will be preserved in the repo unless and until you delete from the repo all snapshots which have references to those segments.
If you restore a snapshot, it will restore all of the segments/shards/indices that were copied from the cluster when you took that snapshot.