Linux
Admin
7 guides
Linux Admin Guides
Users, certs, mail relay Browse 7 linux admin tutorials with step-by-step instructions.
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Popular linux admin how-to guides — good first reads in this topic.
Test Certbot renewal with a dry run
Prove certificates will renew before you get emailed about expiry.
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Install Certbot for Let’s Encrypt
Practical Linux guide: install Certbot for Let’s Encrypt without the usual guesswork.
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Manage users and groups
Practical Linux guide: manage users and groups without the usual guesswork.
Read how-to
Create a sudo user on Linux (not root login)
Daily admin work as a named sudo user — leave root SSH login disabled.
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All Admin guides
7 step-by-step tutorials for Linux.
Test Certbot renewal with a dry run
Prove certificates will renew before you get emailed about expiry.
Read guide
Install Certbot for Let’s Encrypt
Practical Linux guide: install Certbot for Let’s Encrypt without the usual guesswork.
Read guide
Manage users and groups
Practical Linux guide: manage users and groups without the usual guesswork.
Read guide
Create a sudo user on Linux (not root login)
Daily admin work as a named sudo user — leave root SSH login disabled.
Read guide
Add a sudo user on Ubuntu and Debian
Standard admin account setup — no daily root login required.
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Configure logrotate
Practical Linux guide: configure logrotate without the usual guesswork.
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Postfix relay basics
Practical Linux guide: postfix relay basics without the usual guesswork.
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More Linux topics
Explore other guide categories on Linux.
Install & setup
Distro installs, dual-boot, LUKS (12)
Updates
APT, upgrades, package holds (8)
Networking
Static IP, firewall, VPN (14)
Security
SSH, permissions, hardening (10)
Performance
systemd, logs, load, swap (11)
Backups
rsync, restic, snapshots (7)
Storage
mounts, fstab, LVM (7)
Apps & tools
Docker, LAMP, scripting (10)
Troubleshooting
GRUB, boot recovery, services (8)