If you have been working on Linux for some time -- longer than a few years, you probably has come from runlevel days which the services are managed by SysV init scripts. So you are familiar with the commands like shutdown, init, halt, reboot etc. which are used to start, stop or bring the system … Continue reading reboot, shutdown, halt & systemctl
Firewall on Redhat Linux 7 onwards — firewalld, firewall-cmd
With Redhat Linux 7's moving to systemd, not only has the init system been replaced, but other daemons and their utilities have been replaced such as systemd-journald(for event logging), systemd-logind, systemmd-undevd. firewalld has been introduced to replace iptables for managing firewall. It is a service daemon with D-Bus interface. firewalld supports a separation of runtime … Continue reading Firewall on Redhat Linux 7 onwards — firewalld, firewall-cmd
How does systemd maintain the compatibility with SystemV init scripts?
systemd is a system and service manager for Linux operating systems. When a systemd Linux system starts, systemd runs as first process on boot (as PID 1), and it acts as init system that brings up and maintains userspace services. systemd uses "units" (12 different types) to manage services related to system boot-up and maintenance. … Continue reading How does systemd maintain the compatibility with SystemV init scripts?