Server Management

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...

A Windows server can be fully patched and still expose an unnecessary remote administration service. It can also have a carefully restricted firewall ...

When an application cannot reach a server, split the problem into smaller questions. Does the name resolve to the expected address? Can the client est...

A slow file copy, a database timeout and a long login can all involve storage, but they need not have the same cause. Start with the volume used by th...

A busy CPU during a scheduled report is different from a CPU that stays busy after the report finishes. Likewise, a database using a large amount of R...

“The server is down” can mean several different things: a website returns an error, Remote Desktop cannot connect, a file share is slow, or the operat...

Let's Encrypt issues TLS certificates, and Certbot handles requesting, installing and renewing them. This guide uses Certbot's snap installation with ...