By default, Linux only allocates 8192 watches for inotify, which is ridiculously low. And when it runs out, the error is also No space left on device, which may be confusing if you aren't explicitly looking for this issue.
vi /etc/sysctl.conf 增加 fs.inotify.max_user_watches = 262144
# sysctl -p
fs.file-max = 1020000
fs.inotify.max_user_watches = 262144
systemctl daemon-reload
