I recently stumbled upon troubles ¹ trying to run Docker on a fresh CentOS 8 install. Here my notes to spare your (and my) time:

Logtop is an handy log analyzer that can show realtime statistics from any given text file. Common usage example is redirecting the output of your log files to it, in order to get the top visitors of your webpages, or the top hosts requesting pages through your proxy server… all of this in a realtime top list.

Lately I was asked to develop and integrate a realtime server disk usage graph to the dashboard of our monitoring application (OpenNMS). The bar graph color should also change when disk usage exceeds a defined  percentage threshold.

Install PostgreSQL on Debian using APT: # aptitude install postgresql postgresql-client [ after install service is already started and scheduled for automatic start on reboot] Install PostgreSQL on CentOS using YUM: # yum install postgresql-server postgresql

I stumbled upon the problem of fail2ban not banning after I had moved my ssh server to non standard port (let’s say 22022).

..And that’s why I use to hide the most server signatures I can on production servers.

You already know that it is not so smart to leave SSH running on your servers on default port and accessible from every internet address (ie. no firewall restrictions, no host allow/deny).. but in real world it happens to do so since, let’s say, you have no static IP, you have no access to firewall rules and so on.

First of all we install postfix package (if not already installed):

One of our Zimbra Collaboration Suite deployments stopped working all in a sudden: unable to login with given credentials. My first thought: “oh my, they hacked us!”.

Sometime you need to reset MySQL password on a server you have root access to. Here’s a step-by-step how-to to accomplish this task on a CentOS 6 server.

Here’s how you can wake up (turn on) a remote pc using the Wake-On-LAN function of its network card: you just have to issue a command against the remote machine MAC Address.

You have that server you can’t reboot but need to patch the kernel NOW (eg. #kernel flaw found#).. well, you can try this out.