Updated : Mar 09, 2016 in Apache

Testing SSL Connections with SSLyze, Nmap or OpenSSL

Introduction: OpenSSL is a great tool to check SSL connections to servers. The difficulty here is when one want a full scan of all possible…

Updated : Jan 29, 2016 in Bash

Recursively delete files securely: shredding

Description: Every administrator should know that when we delete a file on the hard disk, almost nothing is really deleted. The space used by the…

Updated : Jan 18, 2016 in GlusterFS

Reporting SMART status of RAID disks

Reference site: http://www.cyberciti.biz/faq/linux-checking-sas-sata-disks-behind-adaptec-raid-controllers/ Note: Although Hardware RAID controllers made by other hardware manufacturers here I use Adaptec as an example: Install the software: apt- get…

Updated : Jan 14, 2016 in Bash

Preventing a bash script from running concurrently

Introduction: In order to prevent a bash script instance from running more than once concurrently, here is a small tip on how to write the…

Updated : Dec 10, 2015 in Apache

Creating a web certificate CSR file.

The process of buying an SSL certificate for a web site is usually as follows: - You create a secret key and CSR files using…

Updated : Nov 19, 2015 in Linux

Scanning for viruses on a Debian/Ubuntu server

Situation: Although most viruses would be mostly harmless in a Linux environment if the viruses are just files laying around, BUT since a server is…

Updated : Oct 17, 2015 in Linux

Example of using UFW firewall in Debian/Ubuntu

Introduction: I just started to use the firewall UFW which is a terminal commands based firewall. The tool seemed a bit difficult to understand at…

Updated : Oct 17, 2015 in Apache

Installing pure-ftpd in Debian/Ubuntu

Difficulty with FTP servers and firewall: If you configure a firewall for a host which runs an FTP server you normally need to leave the…

Updated : Aug 25, 2015 in Apache

Limiting the number of connected clients on a VirtualHost in Apache

Problem: When a DDOS attack or a burst of requests are coming at the same time in my Apache2 Web server, the whole server can…

Updated : Aug 20, 2015 in Linux

Verifying the integrity of files with md5sum

In order to transfer files and be sure that they were not compromised on their way to their destinations a method of 'checksumming' the file's…