====== Useful links ======

  * [[https://www.serverdensity.com/monitor/linux/how-to/|80 Linux monitoring tools]]
  * [[https://github.com/firehol/netdata|Netdata real-time performance and health monitoring]]
  * [[https://www.howtoforge.com/nginx-how-to-block-visitors-by-country-with-the-geoip-module-debian-ubuntu|nginx geoip block]]
  * [[https://serverfault.com/questions/567113/apache-2-2-and-http-auth-by-country-with-mod-geoip|apache geoip auth]]
  * [[https://www.tecmint.com/watch-or-monitor-linux-log-files-in-real-time/|Watch log in real time]]
  * [[https://www.percona.com/blog/2017/02/09/using-nvme-command-line-tools-to-check-nvme-flash-health/]]
  * [[https://www.binarytides.com/monitor-disk-io-iotop-cron/|Monitor IOTOP activity]]
  * [[https://jpmens.net/2011/01/13/powerdns-implements-dnssec/|PDNS slave DNSSEC support]]
  * [[https://ops.kickassd.com/openvpn-centos-7-csf-easy-setup/|Install openvpn easy way with csf]]
  * [[https://unix.stackexchange.com/a/363309/100727|Linux install root cert]]
  * [[https://www.tecmint.com/rebuild-corrupted-rpm-database-in-centos/|Rebuild currupted RPM database]]
  * [[http://doc.callmematthi.eu/MiniDLNA.html|MiniDLNA issue's]]