Home.md

@@ -21,6 +21,10 @@ The diagram shows the components of a default setup of the LS.ext system, and ho
 2. Enter the ls.ext directory and make the project: ```cd ls.ext && make```. When the make command has executed you have built the project and all containers should be up and running.
 4. To check the platform integrity, run tests with ```make test```
 
+### Troobleshooting
+
+* Elasticsearch won't start. Make sure your system fulfills Elasticsearch [Important System Configurations](https://www.elastic.co/guide/en/elasticsearch/reference/current/system-config.html). In particular, the default virtual mmap count is likely too low, set using `sudo sysctl -w vm.max_map_count=262144`. [docker for Mac instructions](https://www.elastic.co/guide/en/elasticsearch/reference/current/docker.html#docker-cli-run-prod-mode)
+
 ### In-depth guides for individual components:
 
 *  [[Patron-client|Development Patron-client]]