The segment info record allows empty segments to be leaked

The flush thread writes to disk dirty segment buffers every 5 seconds. A segment buffer is defined to be dirty if the amount of record bytes it contains is greater than zero. Since we always write an info record in every segment at the moment they are created, no segment buffer is ever empty. This means that the flush thread writes to disk almost empty segments every 5 seconds, that waste an additional amount of space because of the padding required by the TAR format.