For more desktop-y stuff. See RHEL/CentOS page for server-y stuff.


GNOME Desktop concepts

Here is a list of things in Fedora/GNOME which it took me a while to figure out the name of:

  • System Tray (GNOME desktop) - this was the area within (usually) the top edge of the screen, where some applications displayed an icon, such as Dropbox, SpiderOak Groups, etc. It has been removed, but you can get it back by installing an extension such as Topiconsfix.

  • Activities Search (GNOME desktop) - this is the search that gets initiated when you press the Super/Windows key and then start typing. It can search Documents, Files, Characters, etc. It can be configured from the GNOME control-center. See SearchProvider.

Switching desktop modes

Ensure Fedora starts up in graphical desktop mode:

sudo systemctl set-default


Test open ports with bash:

cat < /dev/tcp/

Networking with NetworkManager

Networking is provided by NetworkManager (nmcli).

NetworkManager takes it upon itself to keep /etc/resolv.conf updated.

To list all connections that NetworkManager knows about:

nmcli connection

Show the DNS settings for a connection (e.g. a Wifi network connection)

nmcli -f ipv6.dns,ipv4.dns connection show "Hyperoptic 1Gb Fibre 5Ghz"
# or
nmcli c s "Hyperoptic 1Gb Fibre 5Ghz" | grep dns

Modify the DNS settings for a connection - e.g. to set NextDNS:

nmcli con mod "Hyperoptic 1Gb Fibre 2.4Ghz" ipv6.dns xxxx:xxxx::xx:xxxx,xxxx:xxxx::xx:xxxx
nmcli con mod "Hyperoptic 1Gb Fibre 2.4Ghz" ipv6.ignore-auto-dns yes
nmcli con mod "Hyperoptic 1Gb Fibre 2.4Ghz" ipv4.dns,
nmcli con mod "Hyperoptic 1Gb Fibre 2.4Ghz" ipv4.ignore-auto-dns yes

To force an update to /etc/resolv.conf after updating settings on a connection:

sudo nmcli con up "Hyperoptic 1Gb Fibre 5Ghz"

VPN connections

To import a VPN connection from an .ovpn file:

nmcli connection import type openvpn file /path/to/your.ovpn

To make a connection from the command line:

nmcli connection up <connection_name>

To see the logs, in case something goes wrong when trying to connect:

journalctl -u NetworkManager.service

Then press G to see the most recent log entries.


Show all paired Bluetooth devices:

bluetoothctl paired-devices

Un-pair and re-pair (apparently this is supposed to work):

$ DEVICE_ID=11:22:33:44:55:66
$ bluetoothctl
[bluetoothctl] devices
[bluetoothctl] untrust 11:22:33:44:55:66
[bluetoothctl] remove 11:22:33:44:55:66
[bluetoothctl] scan on
[bluetoothctl] scan off
[bluetoothctl] connect 11:22:33:44:55:66
[bluetoothctl] pair 11:22:33:44:55:66

You can connect a device using its Address, e.g.:

$ echo -e "connect 11:22:33:44:55:66" | bluetoothctl
Agent registered
[bluetooth]# connect 11:22:33:44:55:66
Attempting to connect to 11:22:33:44:55:66

Check whether some headphones are detected as headphone or headset:

$ pactl list | grep head

Package management with dnf

Use dnf to install packages from official and non-official repos.

  • Modules in dnf are package groups representing an application, language runtime or set of tools. - e.g. node, nginx, maven, mariadb, ruby, perl.

  • Groups are kind of like modules, but, erm, broader? (can you tell I haven’t a clue what I’m talking about)

dnf and rpm Cookbook

Some things about dnf:

Install something:

$ dnf install <spec> # Where spec can be a package-spec, @module-spec or @group-spec

List all repos:

$ dnf repolist

Add a repository:

$ dnf config-manager \
    --add-repo \

List all installed software:

$ dnf list --installed
$ dnf list --installed mypackage

Install something from an RPM file:

$ dnf localinstall myrpmfile.rpm

Remove a package using rpm:

$ rpm -e packagename

Remove a package but don’t remove “unused dependencies”:

$ dnf remove packagename --noautoremove

Or set clean_requirements_on_remove=false in /etc/dnf/dnf.conf. If still having issues, check if the dependent packages really do have a transitive dependency on the package you’re trying to remove, e.g. trying to remove docker and it also wants to remove container-selinux:

$ dnf repoquery --requires docker | grep container-selinux
container-selinux >= 2:2.2-2

(Yum) Find which group contains a specific package:

yum groupinfo '*' | less +/sendmail-cf

Get the current Fedora version:

$ rpm -E %fedora

What application or command is file <x> used for? Which package put it there?

$ dnf repoquery -l texlive-cancel

$ rpm -qf /usr/bin/mvn

What package requires a specific dependency / can I safely delete a package?

$ dnf repoquery --installed --whatrequires ldacbt

$ rpm --test -e ldacbt
# runs a test 'erase' command...should exit 0 if no dependencies

What’s inside a local RPM file?

$ rpm -qlp ~/Downloads/Insomnia.Core-2020.4.1.rpm

Show dnf history - to see what was installed, and when:

$ dnf history | grep ...

Find out when a particular package was installed:

$ dnf repoquery --installed --qf '%{reason} %{installtime} %{name}-%{evr}.%{arch}' nano-default-editor
unknown 2020-12-02 18:26 nano-default-editor-5.3-4.fc33.noarch


List all modules available:

$ dnf module list

List the modules that are enabled (installed):

$ dnf module list --enabled
Fedora Modular 30 - x86_64
Name   Stream       Profiles           Summary                                                 
ant    1.10 [d][e]  default [d]        Java build tool                                         
gimp   2.10 [d][e]  default [d], devel GIMP                                                    
maven  3.5 [d][e]   default [d]        Java project management and project comprehension tool  
scala  2.10 [d][e]  default [d]        A hybrid functional/object-oriented language for the JVM

Fedora Modular 30 - x86_64 - Updates
Name   Stream       Profiles           Summary                                                 
ant    1.10 [d][e]  default [d]        Java build tool                                         
gimp   2.10 [d][e]  default [d], devel GIMP                                                    
maven  3.5 [d][e]   default [d]        Java project management and project comprehension tool  

Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled

Disable a module if it’s causing problems (e.g. gimp):

$ dnf module disable gimp


Groups are virtual collections of packages, e.g.:

  • @c-development - group containing C Development stuff including gcc-c++.

List all groups:

$ dnf group list --ids
Available Environment Groups:
   Fedora Custom Operating System (custom-environment)
   Minimal Install (minimal-environment)
   Fedora Server Edition (server-product-environment)
   Fedora Workstation (workstation-product-environment)
   Fedora Cloud Server (cloud-server-environment)
   KDE Plasma Workspaces (kde-desktop-environment)

List all installed groups:

$ dnf group list --installed

Install a group:

$ dnf group install <group-spec>

Display package lists of a group:

$ dnf group info <group-spec>

Find which groups contain a package (e.g. gcc-c++):

$ dnf group info '*' | less +/gcc-c++

Non-Fedora repositories

rpmfusion: a place for packages which can’t be distributed in the main Fedora repos, for example:

  • Open Broadcaster Software
  • VLC media player
sudo dnf install$(rpm -E %fedora).noarch.rpm$(rpm -E %fedora).noarch.rpm

[unitedrpms][]: multimedia codecs and addons not available in official Fedora repositories.

sudo rpm --import
sudo dnf -y install$(rpm -E %fedora)-15.fc$(rpm -E %fedora).noarch.rpm

Installing things manually

It seems to be common practice to install things in /opt.

For example, to install an early GraalVM build and add a relative symlink in /opt/java/graalvm:

sudo mkdir -p /opt/java
sudo chown -R tdonohue:tdonohue /opt/java
tar -C /opt/java -xvf graalvm-ce-1.0.0-rc15-linux-amd64.tar.gz
ln -r -s graalvm-ce-1.0.0-rc15 /opt/java/graalvm



Search for fonts:

$ dnf search fonts

Manually install a font:

$ tar xvf the-font-archive.tgz
$ sudo mkdir -p /usr/share/fonts/the-font-name
$ sudo cp *.otf /usr/share/fonts/the-font-name
$ fc-cache -v

Reset the font cache:

$ fc-cache

Resizing images

In Software app, add the image resizer feature to the Nautilus file browser:

$ dnf install nautilus-image-converter
$ nautilus -q

Compressing images

Try Trimage. Installing Trimage on Fedora 29:

$ sudo dnf install jpegoptim pngcrush advancecomp
$ git clone && cd Trimage
$ chmod u+x
$ ./ build
$ sudo ./ install


gnome-software provides the GUI application Software for installing updates:

Problem: “Unable to download firmware updates from ‘fwupd’ … failed to download Cannot resolve hostname”

$ dnf update gnome-software


Disk housekeeping

Checking disk space. Use Disk Usage Analyzer app for a visual analysis of disk space in use. Or use df:

$ df -h /
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/fedora-root   49G   46G  834M  99% /
# Yikes I have hardly any space left! Damn those Docker images.

Keeping the fedora-root partition down to size. Files in /var/cache/PackageKit can reach double-digit GBs. These files are used by GNOME PackageKit (an alternative to dnf?).

  • Prune using pkcon refresh force -c 2592000 (2592000 = 1 month in seconds)
  • You can remove cached packages by executing dnf clean packages
  • Find and remove old Docker images (docker rmi ...). Use docker info | grep "Docker Root Dir" to find the images location and du to check the size:
$ docker info | grep 'Root Dir'
 Docker Root Dir: /var/lib/docker
$ sudo du -sh /var/lib/docker
11G      /var/lib/docker
$ docker system prune
$ docker image prune -a
$ docker volume prune
$ df -h /
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/fedora-root   49G   37G   11G  79% /

Reducing journal size:

  • Journals are kept in /var/log/journal
  • Edit /etc/systemd/journald.conf and set SystemMaxUse=1G
  • systemtl restart systemd-journald


To upgrade Fedora, follow the process described at:

Troubleshooting upgrades

Error when running sudo dnf system-upgrade download ...:

Problem: package gstreamer1-plugins-bad-free-gtk-1.16.2-8.fc30.x86_64 requires gstreamer1-plugins-bad-free = 1.16.2-8.fc30, but none of the providers can be installed
  - gstreamer1-plugins-bad-free-1.16.2-8.fc30.x86_64 does not belong to a distupgrade repository
  - problem with installed package gstreamer1-plugins-bad-free-gtk-1.16.2-8.fc30.x86_64
(try to add '--skip-broken' to skip uninstallable packages)
  • “If some of your packages have unsatisfied dependencies, the upgrade will refuse to continue until you run it again with an extra –allowerasing option. This often happens with packages installed from third-party repositories for which an updated repositories hasn’t been yet published.” (from the upgrade docs)
  • Add --allowerasing to the sudo dnf system-upgrade download command. This will show the packages that will be erased.
Error: Transaction test error:
  file /usr/lib64/ from install of libldac- conflicts with file from package ldacbt-
  file /usr/lib64/ from install of libldac- conflicts with file from package ldacbt-
  • Check which package put the file there: rpm -qf /usr/lib64/ => ldacbt-
  • Check which package requires ldacbt as a dependency dnf repoquery --installed --whatrequires ldacbt
  • View info about the package: dnf info ldacbt
  • Finally, remove it: dnf remove ldacbt


tracker-miner-fs seems to consume 100% CPU:

  • Seems to be a process which indexes files and puts the results in ~/.local/share/tracker
  • Check overall status of the tracker using tracker status
  • See what each individual daemon is doing by using tracker daemon
  • If necessary, delete the files/folders which are causing the daemon to go out of control

Fedora no longer boots into a graphical desktop:

  • systemctl set-default seems to have no effect.
  • See systemctl list-units --type target to see all “targets”, or systemctl list-unit-files --type target.
  • GDM appears to be dead - systemctl status gdm reports inactive

Why the hell is my default editor now nano? Why are Git commit prompts opening Nano instead of vi?

  • Check your environment variables: env | grep EDITOR, you’ll see that this environment variable points to nano as your default editor.
  • To see how it was set, you can run zsh -xl which will list all of the commands that are run when you open a new shell. Within this output is a line somewhere that runs a script: /etc/profile.d/
  • You can see what package installs this file: dnf provides /etc/profile.d/ - it’s the nano-default-editor package.
  • To find out when this package was installed: dnf repoquery --installed --qf '%{installtime}' nano-default-editor
  • Cross-referencing that with the output from dnf history shows that it was installed when I upgraded to Fedora 33. CONTROVERSIAL.

Some websites aren’t loading, and resolve to IP address

  • Some websites/scripts don’t load in the browser.
  • Trying to look up these domains, e.g. nslookup, gives a result of
  • Have a look at /etc/resolv.conf, to see which nameserver you’re using. When I looked, mine was showing
  • is (probably) the address of a caching DNS resolver. Probably resolved. Check its status with: systemd-resolve --status
  • There is a command resolvectl flush-caches, but this didn’t seem to do anything for me. Instead, you might clear the cache by just restarting resolved.
  • To reset the resolved DNS cache, just restart resolved: sudo systemctl restart systemd-resolved