Add known issue for DS MemFree instead of MemAvailable (#2536)

* Add known issue for DS MemFree instead of MemAvailible

* Fix typo

source/docs/yearly-overview/known-issues.rst

@@ -8,6 +8,21 @@ This article details known issues (and workarounds) for FRC\ |reg| Control Syste
 Open Issues
 -----------
 
+Driver Station Reports Less Free RAM then is Available
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+**Issue:** The Driver Station diagnostic screen reports free RAM that is misleadingly low. This is due to Linux's use of memory caches. Linux will cache data in memory, but then relinquish when the robot programs requests more memory. The Driver Station only reports memory that isn't used by caches.
+
+**Workaround:** The true memory available to the robot program is available in the file ``/proc/meminfo``. :doc:`Use ssh to connect to the robot </docs/software/roborio-info/roborio-ssh>`, and run ``cat /proc/meminfo``.
+
+.. code-block:: text
+
+   MemTotal:         250152 kB
+   MemFree:           46484 kB
+   MemAvailable:     126956 kB
+
+The proper value to look is as MemAvailable, rather then MemFree (which is what the driver station is reporting).
+
 Visual Studio Code Reports Unresolved Dependency
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^