Major Description
FileLink assumes that underlying files can be moved while there are open readers. Windows does not allow the file which has active readers to be moved unless the file is opened in shared mode. JDK6 and 7 open the file in exclusive mode by default, so moving the file while there are readers is not possible.
Hadoop-on-windows copies the file, if it cannot perform the rename. This will cause duplication, and the original file not being deleted.
This affects the unit test TestFileLink. On local mode over NTFS, reading from snapshot files and replication might cause issues, but I don't think it has any other implications on hbase+hdfs on windows.