Skip to main content

Linux Server

How to install Apache Security Module in Amazon Linux AMI

Apache mod_security is a firewall module to prevent against SQL Injection, cross site scripting, bad user agents, and a lot of other exploits. 

Depends on the Amazon Linux AMI version you may have to issue one of the below commands on a trial & error basis.

sudo yum install mod24_security.x86_64


knackforge Fri, 06/30/2017 - 14:53
knackforge blog knowledge base
How to apply only security updates in Amazon Linux AMI


The Amazon Linux AMI is a Linux image provided by Amazon Web Services (AWS) for use on Amazon EC2. It is designed to provide a stable, secure, and high performance execution environment for applications running on Amazon EC2.

sivaji Thu, 06/29/2017 - 02:25
knackforge blog knowledge base

How to install and configure Zabbix 3 on Debian 8 (Jessie)

Zabbix is enterprise open source monitoring software for networks and applications. It is designed to monitor and track the status of various network services, servers, and other network hardware. The zabbix server can check standard networking services like HTTP, FTP, SMTP, IMAP etc. We need to install and configure a Zabbix agent  for gathering data about CPU, disks, internal system process, RAM, etc.

Lets check the steps for installing and configuring Zabbix on a Debian 8 server:

Step 1: Install required dependencies:

Restoring removed files (rm -rf) in Linux with TestDisk

There are odd times where we would have accidentally deleted some important folders without having any actual backup. It happened to us, one of our team members on the way to remove a symbolic link, accidentally deleted a webfolder using rm -rf, though we normally maintain GIT repo, for this temporary project, we did not. So we had to restore it though initially it looked gloomy. I stumbled upon "extundelete" but that could not restore any important files. Then we tried See more details below

selvam Wed, 08/10/2016 - 01:47
Restoring Removed Files Linux TestDisk
How we managed to use Tripwire for detecting intrusions

We all should be aware that security is very important for our servers. Having informed about the changes to server file system is always important, as unauthorised access could very well breach security. Here comes our saviour Open Source Tripwire, which is a free security and data integrity tool useful for monitoring and alerting on specific file change(s) on a range of systems. 

Open Source Tripwire functions as a host-based intrusion detection system. It detects changes to file system objects and alerts the server administrator.

suresh Thu, 07/14/2016 - 00:22
Tripwire detecting intrusions
Fix chkconfig

Fix chkconfig command not found

It happened in one of the servers we maintain, chkconfig was installed but it couldn't be loaded. Below are the sequence of commands I used to find the cause and fix.


# It was needed to have tomcat start at boot time

$ sudo chkconfig --add tomcat  
-bash: chkconfig: command not found

# I thought it was not installed but it is in place.

Subscribe to Linux Server