private void verifyConfigs(StoreConfig storeConfig, DiskManagerConfig diskManagerConfig) throws StoreException {
    /* NOTE: We must ensure that the store never performs hard deletes on the part of the log that is not yet flushed.
       We do this by making sure that the retention period for deleted messages (which determines the end point for hard
       deletes) is always greater than the log flush period. */
    if (storeConfig.storeEnableHardDelete && storeConfig.storeDeletedMessageRetentionMinutes
        < TimeUnit.SECONDS.toMinutes(storeConfig.storeDataFlushIntervalSeconds) + 1) {
      throw new StoreException(
          "Message retention hours must be greater than the store flush interval period when hard delete is enabled",
          StoreErrorCodes.InitializationError);
    }
    if (diskManagerConfig.diskManagerReserveFileDirName.length() == 0) {
      throw new StoreException("Reserve file directory name is empty", StoreErrorCodes.InitializationError);
    }
  }
Verify that the {@link StoreConfig} and {@link DiskManagerConfig} has valid settings.
@param storeConfig the {@link StoreConfig} to verify.
@param diskManagerConfig the {@link DiskManagerConfig} to verify
@throws StoreException if the {@link StoreConfig} or {@link DiskManagerConfig} is invalid.
ambry-store/src/main/java/com/github/ambry/store/StorageManager.java