* Initiate a check of the supplied storage volumes and return
* a list of failed volumes.
* StorageLocations are returned in the same order as the input
* for compatibility with existing unit tests.
* @param conf HDFS configuration.
* @param dataDirs list of volumes to check.
* @return returns a list of failed volumes. Returns the empty list if
* there are no failed volumes.
* @throws InterruptedException if the check was interrupted.
* @throws IOException if the number of failed volumes exceeds the
* maximum allowed or if there are no good