ie, if a file is open, and the 'rebalance' command is issued, currently the file is not migrated (even if it has link files). This is a blocker feature to make GlusterFS default filesystem for storing the VM images. With this feature, one can migrate the live-VM, which helps in all practical scenarios.
CHANGE: http://review.gluster.com/209 (Complexity involved: To migrate a file with open fd, we have to) merged in master by Vijay Bellur (vijay)
CHANGE: http://review.gluster.com/408 (* incorporated Avati's comments on the first patch.) merged in master by Vijay Bellur (vijay)