Elasticsearch should be fine for this use-case. Just be sure to keep snapshots. Keeping the original documents is a good idea, so you're able to completely rebuild the indices if the worst happens, or you hit bugs in ingest and need to start from scratch.
Depending on how you define 'really large amount', Elasticsearch could be overkill. If you don't need to distribute the data over multiple nodes and have some Java expertise, using vanilla Lucene is worth thinking about.