Add per index path.data setting

[ntherning]

It would be great to be able to store data files for different indices in different paths. My use case is that I have servers with both fast SSDs and slow HDDs. I'd like to have one of my indices stored on the SSD while the others would be stored on the HDD.

It would also be cool if this setting could be changed at runtime. Then I could move a "hot" index to the SSD and swap out less hotter ones using cron. We use rolling indices based on date and the two most recent ones are the targets of almost all search/index requests.

[spinscale]

You could solve this by using multiple nodes on one host and shard allocation, see http://www.elasticsearch.org/guide/reference/modules/cluster/

[xinuc]

👍 this

I think this is a pretty common use case.
Some indices need the speed of ssd, while the others need the capacity.

[clintongormley]

This gets really complicated with the disk aware shard allocation decider. Best solution is to use shard allocation filtering to assign busy indices to stronger boxes.