Should be able to shutdown elasticsearch, copy the data directory in, then mount in the correct place and restart elasticsearch.
After restarting verify the log file ( /var/log/elasticsearch/labsearch.log) reporst /dev/md1, instead of its current report:
[2015-10-06 03:28:31,460][INFO ][env ] [nobelium] using [1] data paths, mounts [[/ (/dev/md0)]], net usable_space [85.1gb], net total_space [91.4gb], types [ext3]