Merge pull request #11775 from nextcloud/fix/sysreq-low-memory

fix(Requirements): Memory constrained environments

admin_manual/installation/system_requirements.rst

@@ -55,6 +55,11 @@ depending on the numbers of users, apps, files and volume of server activity.
 
 Nextcloud needs a minimum of **128MB** RAM per process, and we recommend a minimum of **512MB** RAM per process.
 
+In low memory environments, some features or apps may require adjustments to their default 
+settings in order to function (or, in some cases, may need to be disabled outright).
+
+.. warning:: To use the built-in Updater, at least 256MB is required.
+
 Database requirements for MySQL / MariaDB
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^