Systems Administration

On modern Linux systems, the easiest and safest way to install software is usually through the distribution’s package manager. It resolves dependencies, tracks installed files, and makes updates and removal much easier than manual installs. Debian and Ubuntu sudo apt update sudo apt install package-name Fedora and RHEL-family systems sudo dnf install package-name Arch Linux … Read more

GnuPG implements the OpenPGP standard and can be used to encrypt files or messages and to create digital signatures. It is still useful, but many older email-client instructions and key-generation examples are no longer current. Generate a modern key gpg –full-generate-key Choose a modern algorithm offered by your installed GnuPG version and protect the private … Read more

Linux software is usually installed through the distribution package manager. This is safer than downloading random installers because packages are tracked, updated and removed cleanly. Debian and Ubuntu systems Red Hat, Fedora and similar systems Older Red Hat-based systems may use yum instead of dnf. Check whether software is already installed Prefer the package manager … Read more

SSH key-based login lets you connect to a remote server without typing the account password each time. It is also the preferred approach for automation, scripts and secure administration. Create an SSH key Use a passphrase unless the key is specifically for controlled automation. Copy the public key to the server Test the login Where … Read more

Legacy note explaining why old Samba Primary Domain Controller setups should be treated carefully today.

A legacy note on hard disk performance tuning and why old hdparm flags should be used carefully today.

Practical Linux rootkit-checking notes covering chkrootkit, rkhunter, logs, package verification, and safer recovery after a suspected compromise.

Installing software from source is useful when a package is not available in the distribution repositories, but it should not be the first choice. Prefer the package manager when possible. Typical source install flow Not every project uses this exact pattern. Always read the project README or INSTALL file first. Install build tools first On … Read more

If a user needs to run a small set of administrative commands, the preferred approach is usually a carefully scoped sudo rule rather than making arbitrary programs setuid root. Use sudo with least privilege Edit sudo policy with visudo or a file under /etc/sudoers.d/. Grant only the exact commands required, and avoid broad rules such … Read more