private String executeOperation(String operationName) throws ServerException {
	StringBuilder output = new StringBuilder();
	try {

	    Process process = Runtime.getRuntime().exec(new String[]{shellScript.getShellScriptPath().getAbsolutePath(), operationName});
	    InputStream in = process.getInputStream();

	    int c;
	    while ((c = in.read()) != -1) {
		output.append(c);
	    }
	    in.close();
	    process.waitFor();
	    int returnVal = process.exitValue();
	    if ((returnVal) != 0) {
		throw new ServerException("Script has terminated with return value != 0: " + returnVal);
	    }


	} catch (InterruptedException ex) {
	    
	} catch (IOException ex) {
	    ex.printStackTrace();
	}
	return output.toString();
    }