Source:
<code>public void start() { if (started) { throw new IllegalStateException("This store is already started!"); } started = true; temporaryTable = new TemporaryTable(configuration.indexQueueLength() * configuration.indexSegments()); storeQueue = new SyncProcessingQueue<>(); indexQueue = new IndexQueue(configuration.indexSegments(), configuration.indexQueueLength()); fileProvider = new FileProvider(getDataLocation(), configuration.openFilesLimit(), "ispn."); compactor = new Compactor(fileProvider, temporaryTable, indexQueue, marshaller, timeService, configuration.maxFileSize(), configuration.compactionThreshold()); logAppender = new LogAppender(storeQueue, indexQueue, temporaryTable, compactor, fileProvider, configuration.syncWrites(), configuration.maxFileSize()); try { index = new Index(fileProvider, getIndexLocation(), configuration.indexSegments(), configuration.minNodeSize(), configuration.maxNodeSize(), indexQueue, temporaryTable, compactor, timeService); } catch (IOException e) { throw log.cannotOpenIndex(configuration.indexLocation(), e); } compactor.setIndex(index); startIndex(); final AtomicLong maxSeqId = new AtomicLong(0); boolean migrateData = false; if (!configuration.purgeOnStartup()) { FileProvider oldFileProvider = new FileProvider(getDataLocation(), configuration.openFilesLimit(), ""); if (oldFileProvider.hasFiles()) { <START> log.debug("Migrate old format to new format."); <END> migrateFromOldFormat(oldFileProvider); migrateData = true; } else if (index.isLoaded()) { log.debug("Not building the index - loaded from persisted state"); } else { log.debug("Building the index"); buildIndex(maxSeqId); } } else { log.debug("Not building the index - purge will be executed"); } if (!migrateData) { logAppender.setSeqId(maxSeqId.get() + 1); } }</code><technical_language>I this log a message indicating migration sucessfully completed info in SFS</technical_language>

Target:
public void start() { if (started) { throw new IllegalStateException("This store is already started!"); } started = true; temporaryTable = new TemporaryTable(configuration.indexQueueLength() * configuration.indexSegments()); storeQueue = new SyncProcessingQueue<>(); indexQueue = new IndexQueue(configuration.indexSegments(), configuration.indexQueueLength()); fileProvider = new FileProvider(getDataLocation(), configuration.openFilesLimit(), PREFIX_11_0); compactor = new Compactor(fileProvider, temporaryTable, indexQueue, marshaller, timeService, configuration.maxFileSize(), configuration.compactionThreshold()); logAppender = new LogAppender(storeQueue, indexQueue, temporaryTable, compactor, fileProvider, configuration.syncWrites(), configuration.maxFileSize()); try { index = new Index(fileProvider, getIndexLocation(), configuration.indexSegments(), configuration.minNodeSize(), configuration.maxNodeSize(), indexQueue, temporaryTable, compactor, timeService); } catch (IOException e) { throw log.cannotOpenIndex(configuration.indexLocation(), e); } compactor.setIndex(index); startIndex(); final AtomicLong maxSeqId = new AtomicLong(0); boolean migrateData = false; if (!configuration.purgeOnStartup()) { FileProvider oldFileProvider = new FileProvider(getDataLocation(), configuration.openFilesLimit(), PREFIX_10_1); if (oldFileProvider.hasFiles()) { PERSISTENCE.startMigratingPersistenceData(); migrateFromOldFormat(oldFileProvider); migrateData = true; } else if (index.isLoaded()) { log.debug("Not building the index - loaded from persisted state"); } else { log.debug("Building the index"); buildIndex(maxSeqId); } } else { log.debug("Not building the index - purge will be executed"); } if (!migrateData) { logAppender.setSeqId(maxSeqId.get() + 1); } }