DOCS-1067 syncdely documentation update

Author: Sam Kleinman

source/reference/configuration-options.txt

@@ -541,18 +541,18 @@ Settings
    :program:`mongod` writes data very quickly to the journal, and
    lazily to the data files. :setting:`syncdelay` controls how much
    time can pass before MongoDB flushes data to the datafiles via an
-   :term:`fsync` operation. The default setting is 60 seconds.  We
-   recommend almost always using the default setting of 60.
+   :term:`fsync` operation. The default setting is 60 seconds.  In
+   almost every situation you should not set this value and use the
+   default setting.
 
-   The serverStatus command reports the background flush thread's
-   status via the backgroundFlushing field.
+   The :dbcommand:`serverStatus` command reports the background flush
+   thread's status via the :data:`~serverStatus.backgroundFlushing` field.
 
-   .. note::
+   .. warning::
 
-      If :setting:`syncdelay` is ``0``, :program:`mongod` flushes all
-      operations to disk immediately, which has a significant impact
-      on performance. Run with :setting:`journal` enabled, which is the
-      default for 64-bit MongoDB builds.
+      If you set :setting:`syncdelay` to ``0``, MongoDB will not sync
+      the memory mapped files to disk. Do not set this value on
+      production systems.
 
 .. setting:: sysinfo
 

source/reference/mongod.txt

@@ -416,21 +416,21 @@ Options
 
 .. option:: --syncdelay <value>
 
-   :program:`mongod` writes data very quickly to the journal, and lazily to the
-   data files. :option:`--syncdelay` controls how much time can pass before
-   MongoDB flushes data to the datafiles via an :term:`fsync`
-   operation. The default setting is 60 seconds.  We recommend almost
-   always using the default setting of 60.
+   :program:`mongod` writes data very quickly to the journal, and
+   lazily to the data files. :option:`--syncdelay` controls how much
+   time can pass before MongoDB flushes data to the datafiles via an
+   :term:`fsync` operation. The default setting is 60 seconds.  In
+   almost every situation you should not set this value and use the
+   default setting.
 
-   The serverStatus command reports the background flush thread's
-   status via the backgroundFlushing field.
+   The :dbcommand:`serverStatus` command reports the background flush
+   thread's status via the :data:`~serverStatus.backgroundFlushing` field.
 
-   .. note::
+   .. warning::
 
-      If :option:`--syncdelay` is ``0``, :program:`mongod` flushes all
-      operations to disk immediately, which has a significant impact
-      on performance. Run with :setting:`journal` enabled, which is the
-      default for 64-bit MongoDB builds.
+      If you set :option:`--syncdelay` to ``0``, MongoDB will not
+      sync the memory mapped files to disk. Do not set this value on
+      production systems.
 
 .. option:: --sysinfo