Engine stuck at 50% indexing

After a large data push (over 200k documents, each document ~1kb), I decided to update the schema to reflect that some of our fields are numbers and not text. The engine started indexing and all seemed fine until it hit 50%. It has been stuck there for hours.

How do I get it to complete? It also seems like the related fields which are getting updated in the schema are not available for some of the documents.

I also suspected that the cause of this may be insufficient space in the Elasticsearch instance (there's another engine that has 2GB worth data). I have since increased the storage to 32GB, but I'll have to wait to see if this fixes the problem.

16GB filled up with data