Cluster issue when Master node has crashed

ES 6.4.3 . i had a cluster with two nodes my master node configured over a Virtual Machine is crashed. prior to the Crash the The monitoring of the cluster showed indexed data as 20 GB. which has reduced to half when i view in the other node which was part of cluster. is it normal or some data might have been lost due to crashing of Master node.

It's best to not create multiple topics about the same question, let's continue the discussion here - Clustering in ES