If your Elasticsearch data node service is refusing to start with this error:
: max virtual memory areas vm.max_map_count  is too low, increase to at least 
You’ve to increase the mmap count limit by running this command:
sysctl -w vm.max_map_count=262144
This temporarily increases the limit, but to persist this change permanently, you have to add the
following line to the
vm.max_map_count = 262144
If you are running Elasticsearch via Docker, you have to restart your Docker container after making this change to the host machine.