How to increase vm.max_map_count?
# sysctl -w vm.max_map_count=262144
And for the persistence configuration
# echo "vm.max_map_count=262144" >> /etc/sysctl.conf
From version 207 and 21x, systemd only applies settings from /etc/sysctl.d/*.conf and /usr/lib/sysctl.d/*.conf. If you had customized /etc/sysctl.conf, you need to rename it as /etc/sysctl.d/99-sysctl.conf. If you had e.g. /etc/sysctl.d/foo, you need to rename it to /etc/sysctl.d/foo.conf.
/etc/sysctl.d/99-sysctl.conf and then run
sudo sysctl --system
To make it persistent, you can add this line:
/etc/sysctl.conf and run
$ sudo sysctl -p
to reload configuration with new value