We would like to store lots of old indices in S3 for easy storage and the ability to import the indice from S3 back into Elasticsearch when needed. I have installed the repository-s3 plugin, and I have seen how i can do snapshots, but can i actually just load individual files into S3 to store and then reimport them when needed? What options do i have here?
That sounds like what the snapshot/restore API is doing, no?
Snapshot and restore does this, as would Searchable snapshots | Elasticsearch Guide [8.8] | Elastic with the added benefit is you don't need to restore to be able to read it.