Category Archives: Linux Maintenance


Install Cinnamon In CentOS

The instructions below assume that you installed Centos minimal without the X windows system. If you already have Gnome running , you can just install the epel repo and then yum install cinnamon.

While there are many different graphical user interfaces available for Linux, in this example we will be using Cinnamon.

First we need to configure the EPEL repository, as this is where we will be installing packages from.

[root@centos7 ~]# yum install epel-release -y && yum update 

Next I needed to install the “Server with GUI” group before proceeding. Note that this will also install GNOME, you’ll be able to change to Cinnamon later though.

[root@centos7 ~]# yum groupinstall "Gnome Desktop" -y

Installing the Cinnamon Desktop is now as simple as installing the “cinnamon” package, which then has many dependencies to install many more packages that are required for a GUI installation.

[root@centos7 ~]# yum install cinnamon -y

Remember to set the systemd graphical target
systemctl set-default

More information

Debian Upgrade to 9

Debian Distro upgrade. For this example we are upgrading from jessie to stretch
# apt-get update
# apt-get upgrade
# apt-get dist-upgrade

sed -i 's/jessie/stretch/g' /etc/apt/sources.list

# apt-get update
(if you receive a error similar to E: Release file expired. run apt-get -o Acquire::Check-Valid-Until=false update )
# apt-get upgrade
# apt-get dist-upgrade

some housekeeping after the upgrade. The below commands will remove old packages from the system
# Check dpkg -l | awk '/^rc/ { print $2 }'

# apt-get purge $(dpkg -l | awk '/^rc/ { print $2 }')
# apt-get autoremove

IP-tables config

Block an IP
iptables -I INPUT -s -j DROP

After rebooting the server we notice the rules are removed. It’s best to save your configs and restore them after a reboot.
iptables-save > /etc/iptables/rules

iptables-restore < /etc/iptables/rules

flush all rules
iptables -F

flush rules in the input chain
iptables -F INPUT

iptables -L –line-numbers

iptables -D INPUT 3 – delete a line

Fedora : Untrusted Application Launcher


The application launcher *.desktop has not been marked as trusted. If you do not know the source of this file, launching it may be unsafe.

Then there is no other options available to you. I found this to be a permission issue if you downloaded the application as root. The app group will need to be changed to a users group with executable rights.