Most system administrators know the tail command. By default, it displays the 10 last lines of a file. The -f option is less known. Besides displaying the last 10 lines of a file, it mainly provides a way to watch…

Many people who had registered to buy the new version of Michael Jang‘s book for the RHEL  7 just received an email today announcing its publication on March 31. This new edition was expected since the beginning of last year…

When preparing an exam like the RHCSA or the RHCE exams, it is relatively difficult to remember the commands with all their options, the configuration procedures with all their details, and finally the mistakes to avoid. This is even worse…

When using the new RHEL 7.2 release and running the systemctl status command, some slight changes were recently visible: # systemctl status sshd ● sshd.service – OpenSSH server daemon Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; vendor preset: enabled) Active: active (running) since…

Among the changes coming with the RHEL 7.2 release, there is the new systemctl edit command. Like the systemctl cat command, you specify a service unit file as argument. But, unlike the systemctl cat command, you will need to think twice…

In a previous post, I presented the various mechanisms used for customizing Systemd unit files. These mechanisms are so rich that it is not easy to get the real picture of the final unit file. You have to search in…

From my understanding, Systemd was created to make the maintenance of Linux distributions easier. With previous init systems, you had to know all packages that could interact with a given subsystem, and you had to know them for each distribution for…