High disk watermark exceeded even when there is not much data in my index

Question

I\'m using elasticsearch on my local machine. The data directory is only 37MB in size but when I check logs, I can see:

[2015-05-17 21:31:12,905][WARN

Answer 1

From Index Shard Allocation:

... watermark.high controls the high watermark. It defaults to 90%, meaning ES will attempt to relocate shards to another node if the node disk usage rises above 90%.

The size of your actual index doesn't matter; it's the free space left on the device which matters.

If the defaults are not appropriate for you, you've to change them.