Server Management

A fresh Ubuntu Server installation is a starting point, not a finished service. Before putting an application on it, verify the release, maintenance p...

SSH is a powerful remote administration channel, so protect both the account and the path that reaches it. Moving the listener to another port can red...

An AutoSSL request that remains pending is waiting on a validation or provider step. Repeatedly clicking “Run AutoSSL” may produce more requests witho...

Moving an SSH server to key-based authentication can improve account security, but changing the server before testing the key creates an avoidable loc...

iptables is a command-line interface to Linux packet-filtering rules. Before editing a server firewall, find out which tool manages the rules and whet...

Installing unattended-upgrades does not, by itself, tell you whether a machine is applying the updates you expect. Configuration, timers, repository s...

A query can be slow because it reads too many rows, repeats an operation many times or waits on work outside the part you measured. EXPLAIN ANALYZE he...

UFW provides a convenient way to manage a host firewall on Ubuntu. The dangerous moment is often the first enable command on a remote server: if the a...

When a user cannot sign in, restarting a domain controller is rarely a useful first test. Determine whether the failure affects one account, one works...

A server that restarted overnight has not necessarily suffered a blue-screen crash. Power loss, a hypervisor action, an administrator restart and a Wi...