Failed to allocate directory watch: Too many open files

# /etc/sysctl.conf
# fs.inotify.max_queued_events = 16384
# fs.inotify.max_user_instances = 128
# fs.inotify.max_user_watches = 8192
fs.inotify.max_queued_events=1048576
fs.inotify.max_user_instances=1048576
fs.inotify.max_user_watches=1048576

https://easyengine.io/tutorials/linux/increase-open-files-limit/