How to Uninstall Unused Old Kernels
cloudibee During updates your old Linux kernels pile up. Then one day when you try to do your next updates, an interesting alert comes up from the server. Basically, it tells…
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How to Password Protect a Directory on Apache
First, you need to create a password file. Exactly how you do this will vary depending on what authentication provider you have chosen. More on that later. To start with,…
Resilience Against Buffer Overflows
Like its big brother Sendmail, Postfix is an open source mail transfer agent (MTA) for routing and delivery of e-mail. It is fast and easy to administer. You can even…
Troubleshooting Linux and MySQL Introduction
One Web Site Instead of All Books Honestly, my dream is to find a great book on Apache server. From time to time I still keep this dream alive by…
How to free a lot of memory and drop caches
In my Web Analytics company, I occasionally had problems with Linux servers, because they tended to cache a lot of stuff. Especially, this problem occured, when I was manually copied…
The Spamhaus Project
I have nothing but the utmost respect for the Spamhaus project. What is Spamhaus? For those who don’t know I wll reproduce the quote from its web site: “Spamhaus tracks…
Secure your Apache Configuration and IPTables: Blacklists
20 ways to Secure your Apache Configuration This is a pretty good basic/intermediate Howto written by Pete Freitag, who is a software engineer, and web developer from central New York.…
How to format external USB Drive to Fat 32
When I purchased my first external USB drive, I wanted immediately to add it to my Linux system. Yet, no matter how hard I tried, rebooting my hard drive over…
How to set up Squirrelmail (Webmail) and configure Sendmail
Ok, so you installed and set up Sendmail and Dovecot and they are working in sync without any problems. What’s next? Here comes webmail. If you don’t want a workhorse,…
Dovecot’s Miracle and Do You Wanna… Samba?
Miracle software with a simple name Dovecot Over the years I used Dovecot as a companion for Sendmail. It is getting better with the time. In early versions I had…
Linux commands, Bind Configuration and Free DNS Tools
Linux Commands If you need to find out quickly what a certain Linux/Unix command means, this manual comes really hand. It will provide you with all commands from A to…
Identifying SSL Certificate Algorithm using nmap and openssl command
SSL certificate signature algorithm can be identified using nmap or openssl command. Here are the steps to identify SSL certificate algorithms used in your webserver or other SSL endpoints. nmap…
Writing C software without stdlib
Major credits to http://betteros.org/ which got me into researchinglibc-free programming. Why would you want to avoid libc? Your code will have no dependencies other than the compiler. Not including the…
Disabling TLS 1.0 on Apache Linux Server
TLS 1.0 is end of life on June 30, 2018. To disable TLS 1.0 on Apache webserver installations, edit the “SSLProtocol” directive in your ssl.conf (typically /etc/httpd/conf.d/ssl.conf), where the ciphers…
Linux Performance analysis tools
Understand how various Linux performance monitoring tools behave when the system is heavily loaded in terms of cpu, memory and swapping to disk (IO).