-# The default is "no" since it's faster and anyway safer than snapshots from
-# the point of view of durability of the latest records modified.
+# The default is "always" that's the safer of the options. It's up to you to
+# understand if you can relax this to "everysec" that will fsync every second
+# or to "no" that will let the operating system flush the output buffer when
+# it want, for better performances (but if you can live with the idea of
+# some data loss consider the default persistence mode that's snapshotting).