Ping is a program that is used to test the reachability of a host. It also measures the time it takes to send the packet and receive one. It does this by sending a ICMP echo request packet and waiting for a reply. Pretty much all Linux flavours will come with Ping pre-installed. How to […]
How to change mac address on Linux temporarily
Whats a MAC address? A MAC address is a physical way of addressing your network card at a hardware level. How to find out your MAC address? Open up a terminal and run: $ ifconfig wlan0 | grep HWaddr Where I have wlan0 you would put your networking device. My output: wlan0 Link encap:Ethernet HWaddr […]
How to change the hostname on ubuntu server
Your hostname is a label that is assigned to your computer so that it can be identified. There are only a couple of steps: Step 1 Edit /etc/hosts: $ sudo vi /etc/hosts You dont have to use vi you can open it with any text editor. Here you should see your current hostname, change it […]
How to install Raspian on the raspberry pi
There are lots of different ways of installing Raspian to an sd card like win32diskimager and usb image writer but an even easier way is with dd. Things I am going to show you: How to locate your sd card in the command line. Where to download the image from. How to install the image […]
How to use apt-get on debian or ubuntu systems
The advanced package tool, also known as APT is a tool that is used for the easy installation, removal and upgrading of software on Debian/Ubuntu systems. Things that I will show you how to do: Search for packages using apt-get Update system package lists Upgrade software packages Install and remove specific software packages Check for […]
How to check the Apache Tomcat and Apache Httpd version in Linux
Tomcat versions can be obtained by version.sh in bin directory of TOMCAT_HOME. HTTPD component version can be viewed using httpd -V command in sbin directory of HTTPD_HOME. # [TOMCAT_HOME]/bin/version.sh # [HTTPD_HOME]/sbin/httpd -V For example: Apache Tomcat $ /opt/jws3/tomcat8/bin/version.sh Using CATALINA_BASE: /opt/jws3/tomcat8 Using CATALINA_HOME: /opt/jws3/tomcat8 Using CATALINA_TMPDIR: /opt/jws3/tomcat8/temp Using JRE_HOME: /home/rhel7/jdk8 Using CLASSPATH: /opt/jws3/tomcat8/bin/bootstrap.jar:/opt/jws3/tomcat8/bin/tomcat-juli.jar Server version: […]
Configure Systemd Service to Continue to Run when the user session ends (CentOS/RHEL 8)
Question: When a user logs out of their session any service they’ve started using the systemd user process is terminated. How this can be avoided? The systemd login manager will terminate any user services when their login session ends unless you enable user lingering with the enable-linger option. Use loginctl with the enable-linger option to […]
What is sticky bit in Linux
A directory whose sticky bit is set becomes an append-only directory, or, more accurately, a directory in which the deletion of files is restricted. A file in a sticky directory may only be removed or renamed by a user if the user has write permission for the directory and the user is the owner of […]
Unable To Mount Samba Share when FIPS is enabled
The Problem Unable to mount Samba share. Attempting to create a mount for a samba share fails. However is accessible with smbclient. /var/log/messages have below errors: Apr 3 22:29:53 localhost kernel: CIFS VFS: could not allocate crypto hmacmd5 Apr 3 22:29:53 localhost kernel: CIFS VFS: could not crypto alloc hmacmd5 rc -2 Apr 3 22:29:53 […]
What are Oracle Data Guard Protection Modes and how to configure them
Data Protection Modes and Redo Transport When you define a redo transport mode, you are configuring the shipment of log files from a redo source to a redo destination. The redo source is usually a primary database or a Far Sync instance. A redo destination is usually a physical or logical standby database. It is […]