git has a very simple solution to see all the commits in a graphical form. If you need to understand all the commits history all you need is
git graphviz|dot -Tpng -o /tmp/a.png
This will generate a file called /tmp/a.png which will diplay the complete commit history.
firewalld by default does not allow packets that are dropped. In some cases, you need to find out if some packet is being dropped or not. For doing so you may want to enable logging of dropped packets with the following command:
sudo firewall-cmd --set-log-denied=all
This will enable logging all the packets and help you figure out if firewalld is dropping the packet.
Sometime back I noticed that whenever I run my favourite command, viz.
journalctl -xn -f -l
it was taking more time than usual. So, I thought to dig more into it and finally found that the following command:
sudo journalctl --disk-usage
showed that journalctl was using some huge space in tune of about 4GB. So, the solution was simple, vaccum the journal entries and the command to do so is :
sudo journalctl --vacuum-size 90M
Checking journalctl size after that confirms the size is reduced and after that indeed the above journal command takes no time 🙂