Guides tagged “linux”
Step-by-step MdmHost guides about linux, sorted A-Z.
280 guides · page 12 of 14
Set up a UFW firewall on Ubuntu and Debian
Set safe defaults, allow SSH before switching UFW on, open only the ports you use, limit sensitive ports to your own IP, and tidy up old rules.
Set up a WireGuard VPN server on a Linux VPS
Install WireGuard on an Ubuntu or Debian VPS, create server and client keys, enable forwarding and NAT, and connect from Windows, macOS or a phone.
Set up Apache virtual hosts for multiple websites
Host several websites on one Apache server with name-based virtual hosts. One config file per domain, its own document root and its own logs, on Ubuntu, Debian, AlmaLinux and Rocky Linux.
Set up IPv6 on a Linux VPS and test it
Add the IPv6 address and gateway from your provider with Netplan or nmcli, open the firewall, publish AAAA records and confirm IPv6 works end to end.
Set Up MySQL Primary-Replica Replication on a Linux VPS
GTID-based MySQL replication between two Linux VPS: set server-id and binary logging on the primary, take a consistent snapshot, then point the replica at it and verify.
Set up Nginx as a reverse proxy for any backend app
Put Nginx in front of a Node.js, Python, Go or Java app running on a local port, forward the right headers, tune timeouts and buffering, and add free HTTPS.
Set Up PostgreSQL Streaming Replication on a Linux VPS
Configure a PostgreSQL primary with a replication role and slot, clone it with pg_basebackup, and bring up a standby that streams WAL in real time.
Set up SSH keys
Create an SSH key pair, add it to your Linux VPS from macOS, Linux or Windows, and optionally switch off password logins safely.
Set up Termius to manage your Linux servers
Use Termius to connect to your Linux VPS from desktop and mobile, add hosts and SSH keys, organise servers into groups, save snippets, transfer files over SFTP and understand the security trade-offs of syncing.
Set your server hostname and reverse DNS
Change the server's hostname, point DNS records at your IP, set reverse DNS in the control panel and check that forward and reverse lookups match.
Setting up a private reverse proxy with Nginx and an internal API
Keep an internal API off the public internet by binding it to loopback or a private address, then let Nginx publish only the routes you choose. Includes firewall, TLS and SELinux notes.
Show real visitor IPs in Nginx behind Cloudflare or a proxy
Behind Cloudflare or a load balancer, Nginx sees the proxy's IP instead of your visitors'. Use the real_ip module to restore the real address for logs, rate limits and apps.
Smaller Docker images with multi-stage builds
Use Docker multi-stage builds to separate build tools from the runtime image. Worked examples for Node.js, Go and Python, plus slim base images and layer caching tips.
SSH Hardening: Auditing and Limiting Shell Access for Service Accounts
Audit every Linux account that has a login shell, move service accounts to nologin, and restrict SSH with AllowGroups and Match blocks so only people who need a session get one.
SSH Hardening: Auditing and Restricting Authorized Keys for Critical Services
Find every authorized_keys file on your Linux VPS, validate each key, and apply strict per-key restrictions so only the access you intend is possible.
SSH Hardening: Enforcing Key Rotation Policies for Automated Security
SSH key rotation replaces long-lived credentials before they become a permanent backdoor. This guide covers expiry dates in authorized_keys, a rotation script and auditing.
SSH Hardening: Mitigating Man-in-the-Middle Attacks with Host Key Verification
SSH host key verification makes your client confirm the server's identity before you send credentials. This guide shows how to read fingerprints, verify them out of band, pin them in known_hosts and rotate host keys without locking yourself out.
SSH into your VPS from a Mac with Terminal
Connect to your Linux VPS from macOS with the built-in Terminal or iTerm2, create an SSH key, store its passphrase in the macOS Keychain and save shortcuts in your SSH config file.
SSH tunnels: local, remote and dynamic (SOCKS) port forwarding
Use SSH port forwarding to reach a private database, expose a local service temporarily, or browse through your server with a SOCKS proxy.
Stop Docker from bypassing your UFW firewall
Docker-published ports skip UFW rules and stay open to the internet. Learn why it happens, how to bind ports to 127.0.0.1, how to filter with the DOCKER-USER chain and how to test from outside.
Browse by topic
- Getting startedYour first hour with a new server: access, logins and basics.69 guides
- cPanelFiles, databases, email, domains and every cPanel tool, step by step.37 guides
- WHM & resellingWHM, packages, reseller accounts, WHMReseller and running a hosting brand.49 guides
- WordPressInstall, secure, speed up, migrate and fix WordPress sites.40 guides
- Email & webmailMailboxes, webmail, forwarders, spam filters and email delivery.37 guides
- DomainsRegistering, transferring and managing domains and nameservers.20 guides
- SSL certificatesFree AutoSSL, Let's Encrypt, paid certificates and HTTPS.19 guides
- CloudLinuxCloudLinux setup and use: LVE limits, CloudLinux Manager, CageFS and PHP/Node.js selectors.31 guides
- LiteSpeedLiteSpeed Web Server, LSCache and the LiteSpeed Cache plugin: install, settings and tuning.30 guides
- Imunify360Malware scanning, firewall and proactive defence with Imunify360.23 guides
- SoftaculousInstall, update, clone and back up apps with Softaculous.23 guides
- WP SquaredcPanel's WordPress platform: sites, plugins, staging and backups.9 guides
- SitePadBuild and publish websites with the SitePad builder.9 guides
- SitejetDesign, edit and publish sites with the Sitejet builder.9 guides
- WHMResellerAlpha and master resellers with WHMReseller: install, setup and use.12 guides
- VirtFusionInstall, set up and manage VirtFusion: hypervisors, packages, servers and WHMCS integration.7 guides
- VirtualizorManage your VPS with Virtualizor: power, OS reinstall, VNC, IPs and backups.30 guides
- PleskWebsites, email, databases and settings in the Plesk panel.52 guides
- DirectAdminUsers, domains, email and reseller tools in DirectAdmin.40 guides
- WHMCSBilling, automation, products and client management with WHMCS.51 guides
- Control panelscPanel & WHM, Plesk, DirectAdmin and other panels on your VPS.106 guides
- SecurityKeys, passwords, firewalls and keeping a server patched.115 guides
- Networking & DNSIP addresses, reverse DNS, ports and traffic.34 guides
- Websites & appsWeb servers, WordPress, PHP, Node.js, SSL and app hosting.52 guides
- DatabasesMySQL, MariaDB, PostgreSQL, Redis and MongoDB on a VPS.64 guides
- Billing & accountInvoices, renewals, the client area and your account.9 guides
- TroubleshootingWhen something is not working: checks and fixes.68 guides
- Linux VPSSSH, packages, services and everyday Linux administration.70 guides
- Windows VPS & RDPRemote Desktop, Windows Server settings and Admin RDP tips.58 guides
- Docker & DevOpsContainers, Git deploys, automation, monitoring and backups.58 guides
Still stuck?
Ask MdmHost AI for a quick answer, or open a ticket and our team will take a look. We are here 24/7.