Setup High Availability for HAProxy


To prevent service failure during disasters like server crash or so on, we have to find Single Point of Failure components and setup High Availability solutions for them. In this article I am going to define how to setup High Availability for HAProxy service. The structure of service would be something like below: In this […]

sudo without password


Typing password for sudo commands is an awful experience. So here’s what we should do to stop linux asking for password: 1. Backup the sudoers file: 2. Open the sudoers file for edit: 3. Edit sudoers file:

Fedora 33: Problem with Broadcom Wifi Device


I am using Fedora workstation as my main OS on my laptop for many years, but usually I face a problem with my wifi device when I try to update my OS or change it. So, here is a solution to fix the problem: First, you have to determine your wifi device model by this […]

How to make Apache HTTPD Web Server more secure


There are some known security issues that can make an Apache HTTPD Web Server insecure. If using Apache HTTPD as a web service is your approach, then you should scan your web server in first step. There are many tools to scan a web server. here we will use NIKTO. Nikto is a free tool […]

How to setup a loadbalancer with HAProxy in RedHat 7

You have many options to install and configure a loadbalancer in RedHat 7. One of the best options is HAPorxy. To setup HAProxy, you have to download related RPM file and then install it: Then, you have to make changes in config file (/etc/haproxy/haproxy.conf): in this sample we have 4 servers as below: Then you […]

Add New Disk to RedHat-based Linux without reboot

If you add a new disk to your OS, you won’t find this device in the device list (fdisk -l command). So you have two options to make it available: Reboot your machine Make the OS rescan all connected devices In operational environments, the first option is not considerable. So we have to choose the […]