code: @Override
  	public String startDeleteSnapshot(String snapshotName) {
  		String jobID = consNextJobID();
  		String jobName = consJobName("deleteBackup", snapshotName);
  		LongJob job = getNode().consDeleteSnapshotJob(jobID, jobName, snapshotName);
  		startJob(job);
  		return jobID;
  	}
docs: Starts the asynchronous operation (- "long job") that will delete
  specified data snapshot. It is empty job if specified snapshot does not
  exist. The operation will be completed with FAILED status if storage node
  is not in NORMAL mode.
  
  @param snapshotName
  The name of snapshot.
  @exception java.lang.IllegalStateException
  If other job is executing currently.