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Tag Archives: centos

Centos: How to fine tune your Apache SSL server


The fine tuning of the SSL server side configuration is slow and tedious but necessary procedure. It’s always good to have your SSL site to conform the most latest security standards. It boosts ego and makes customer happy too. It turns out that all you need for that is already at your disposal the point is to properly configure it.
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Sysadmin: Brute force detection – custom rule for SMTP and SSH

I wrote before about excellent tool BFD that allows to block brute force password guessing attempts on different network services.
I prefer it to Fail2ban because of portability (bash script) system resource consumption (bash script!) and extendаbility (true “unix way” modularity).
I also wrote before a brief instruction on how to extend BFD with your own rule to fight with apache/Wordpress DOS attack.
In this post I will show you how to write custom rules to block SMTP password guessing brute force attempts and SSSHD

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sysadmin: cPanel installation script detected MySQL and failed

While trying to install cPanel control panel on just reimaged server I’ve got an interesting error, I’ve never seen before:

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Sysadmin: “[warn-phpd] mmap cache can’t open file … ” mystery solved


Yesterday I was asked by one of our old customers to help solving very interesting problem – he put some php files outside of apache DocumentRoot on his server and the apache could not access the files, producing very interesting lines into apache default error_log

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Centos: How to run multiple mysql instances on a single server

centos_iconmysql There are plenty instruction on how to run multiple mysql instances on a single server on various blogs. Most of them are based on the original mysql rpm package produced by Oracle (nowdays). In my opinion this could be unnecessary overhead when you have OS provided mysql server package and all you need to configure another instance is to slightly modify bundled configuration and init.d script.
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Centos: cPanel update demands to upgrade MySQL

cpblocked-btn I’ve hit cpanel update “blocker” the other day going from version 11.38 to 11.40.

cPanel update demands to upgrade MySQL and would not take no for an answer – why?
MySQL version 5.1 hits end-of-life on December 2013 and even though Red Hat mysql 5.0 is different from vanilla version and has to be supported until the end of Centos 5 support, cPanel wants to cover all bases and we really don’t have a choice in the situation.
Now, what we should to to continue?
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Centos: How to configure DKIM for sendmail on multiple domains

dkim I wanted to configure DKIM for sendmail on multiple domains for one of the dedicated servers and found out that there are no usable instructions for CentOS and few that are available are inconclusive (I will provide the list of information sources at the end of this post). Here is my tested working setup:
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Sysadmin: Why CentOS?

centos_icon Why CentOS as our main server farm Linux distribution? I really want this article to be pure technical, but there are some emotions attached to the question so please forgive me if I might break into rant somewhere down the road.

There were so many times when I was asked by young men with bright eyes and too much free time on their hands “Why do you use Centos for your server farm? Why not (debian,ubuntu, gentoo, insert your favorite distribution here)?” And I am so tired of explaining this decision over and over so I decided to put it together in this article and get it over with once and for all.
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Centos: How to run additional apache instance on different port

In some situations you might need to configure and run additional apache httpd instance listening on different port. It is really easy to accomplish using minimal modifications to the standard CentOS apache httpd configuration and init script.
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Centos: Quick’n’easy howto install node.js

Unfortunately I could not find proper node.js RPM available, so I had to resort to building it from source. Completely against RH ideology but what else you can do?
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