Linux
RHEL Basics #2: Setup — Installing RHEL 9, Subscription Manager, First Login
Grab the RHEL 9 ISO via Developer Subscription, build a VM in UTM or VirtualBox, walk through the Anaconda installer, register with subscription-manager, and clean up the small post-install items (hostname / time / dnf update / sudo user) — all in one pass.
RHEL Basics #1: What Is RHEL — From Fedora to RHEL, plus AlmaLinux and Rocky Linux
Fedora is where new technology gets tried first; what survives flows into RHEL. CentOS Stream sits in the middle as a preview of the next RHEL, and AlmaLinux and Rocky Linux have settled into the role of free RHEL-compatible distros. Here's the shape of the RHEL ecosystem after CentOS, in one read.
Linux hardware clock time sync
When operating a Linux system, you sometimes need to manually sync the clock because the hardware clock and the OS clock are out of sync. In that case, first check the sync state with the `timedatectl` command.