if(useDisk) {
// start the file storage manager in clean state
// wise FileStorageManager is smart enough to clean up after itself
cleanDirectory(bufferDir);
// Get the properties for FileStorageManager and create.
fsm = new FileStorageManager();
fsm.setStorageDirectory(bufferDir.getCanonicalPath());
fsm.setMaxFileSize(maxFileSize);
fsm.setMaxOpenFiles(maxOpenFiles);
fsm.setMaxBufferSpace(maxBufferSpace*MB);
fsm.initialize();