We have ES 1.7
I've tried to add data directory to path.data both comma delimited or array: path1,path2 or ["path1","path2"]
After rolling restart I got a lot of following:
[INFO ][indices.store ] [node1] Failed to open / find files while reading metadata snapshot
and all indeces gone.
Removing second path and restarting cluster nodes again helped to get almost all data back.