The guide explains how to restore quick file lookup on CentOS 8 by installing the lightweight mlocate tool, which is missing from default installations. It walks through checking that the AppStream repository is enabled, using `dnf install mlocate`, and running `updatedb` to build the search database so future queries return instant results. The author offers practical usage tips such as searching for specific filenames or case‑insensitive patterns with `mlocate -i`, plus a real‑world anecdote where an upgraded system’s sshd_config was found instantly after installing mlocate. Common pitfalls are highlighted—including forgetting to run `updatedb` and the need for superuser privileges—while the article notes that content searches still require tools like grep or ripgrep.

How to install mlocate on CentOS 8 and get your file‑searching back in a snap

CentOS 8 ships without the handy mlocate tool that lets you find files by name instantly. If you’ve ever tried find / -name foo.conf only to stare at hours of output, installing mlocate is the fix. This guide shows you the exact dnf commands, explains why each step matters, and shares a quick tip I learned from a friend who ran into the same issue after an upgrade.

Why install mlocate on CentOS 8?

When you’re hunting for a config file or a log that disappeared during a system tweak, mlocate gives you a quick lookup against a pre‑built database. The database is refreshed once daily by default, so most of the time you’ll get instant results instead of sifting through directory trees.

Step 1: Make sure the AppStream repository is active

CentOS 8’s core packages live in AppStream, but sometimes your system is set up to use only BaseOS. Run:

sudo dnf repolist all | grep appstream

If you see enabled, you’re good. If not, enable it with:

sudo dnf config-manager --set-enabled AppStream

Enabling the repo is crucial; without it, dnf can’t find mlocate.

Step 2: Install mlocate

sudo dnf install mlocate

The install pulls a small package (~70 KB) that contains the command and its database scripts. It’s lightweight compared to bloated “find‑all‑in‑one” GUIs you’ve seen in other distros.

Step 3: Build the initial database

After installation, run:

sudo updatedb

This populates /var/lib/mlocate/mlocate.db. The first build can take a minute on a machine with many files; future searches will be instant. You only need to run this again if you add or remove large directories that should be searchable.

Step 4: Use mlocate

mlocate sshd_config

If you’re looking for multiple patterns:

mlocate -i '*.conf'

The -i flag makes the search case‑insensitive, which is handy when you’re not sure how a filename was capitalized.

A real‑world observation

I once helped a friend who upgraded from CentOS 7 to 8. He ran grep /etc/ssh/sshd_config across /etc and got no hits because the file had moved into /usr/libexec. After installing mlocate, he searched with mlocate sshd_config and found the new location within a second—no more guessing or manual grep loops.

Common pitfalls

• Forgot to run updatedb? You’ll get an empty result set even though the file exists. The database is out of date until you update it.
• Running as root only once? updatedb requires superuser rights because it scans system directories. If you try as a normal user, it will silently skip many paths.

When mlocate isn’t enough

If you need to search by content (not just name), grep -r, ripgrep, or ack are better tools. But for quick file location on CentOS 8, mlocate is the lightweight go‑to solution.