System Logging Linux

System Logging Linux System logs must be recorded for the auditing the system and troubleshooting the problems. By Convention all logs are recorded in the /var/log directory. Syslog message is handled by two services systemd-journald and rsyslog. systemd-journald daemons collects log messages from the kernel, early stage of boot process,[…] Continue reading


OpenSSH OpenSSH is used to securly run a shell on remote system. If you have user account on remote linux system providing ssh service running on the system. ssh is the command to is used to normally used to log into the remote system. The ssh command can also be[…] Continue reading

Systemd in Linux

Systemd in Linux Systemd: Systemd, init – systemd system and service manager for Linux operating systems. When run as first process on boot (as PID 1), it acts as init system that brings up and maintains userspace services. This program provides a method for activating system resources, server daemons, and[…] Continue reading

Sudoers File In Linux

Sudoers File In Linux Default sudo security policy plugin. The sudoers policy determines a user sudo privileges. The policy config file is /etc/sudoers. visudo command is the safe way to edit sudoers file. root user and only user with sudo access can edit the file /etc/sudoers. User Privileges Syntax: user[…] Continue reading

Invalid Signature Kali Linux update Fixed

Invalid Signature Kali Linux update Fixed If you don’t update Kali regularly, then your archive-keyring package is outdated, and you’ll get key mismatches when working with Kali Linux repositories. So when one try to execute command sudo apt-get update will get error as below: W: Failed to fetch The[…] Continue reading

Red Hat Subscription Manager

Red Hat Subscription Manager Red Hat Subscription Management allows users to track their subscription quantity and consumption. Using Subscription Management commands Type man subscription-manager or run subscription-manager with no options to see the syntax for the command. Registering and Subscribing # subscription-manager register –username=yourusername –password=yourpassword The system has been registered[…] Continue reading