If you use GNU/Linux and you are only on opensource, you may be doing it wrong. Here’s why. Is your company based on opensource based software only? Do you have a bunch of developers hitting some kind of server you have installed for them to “do their thing”? Being it for economical reasons (remember to […]
Abandon Linux. Move to FreeBSD or Illumos.
How to replace a disk on a ZFS mirror pool
It’s happened to me, it’s happened to you, it’s happened more than one million times and it will still happen in the future. You run out of disk space or a disk fails. Nowadays you are using ZFS, and instead of having a fancy RAIDZ, because you still don’t need it, you are using a […]
How to install sudo in FreeBSD
Sudo is a very useful application. It allows a regular user to perform tasks only reserved to the root account. There is lots of documentation about sudo and there is even a book about it called “Sudo Mastery”. If you need to investigate deep on this, buy it. Why do you need this? Well… Everyone […]
How to configure the PF firewall on FreeBSD
There are three firewall options on FreeBSD. The in-house built IPFW, the ‘old’ IPF (known as IP Filter) and PF ported from OpenBSD. PF is a very popular piece of software which was originally sparked from an issue on the IPF license that prevented making changes publicly available, which the OpenBSD did all the time. […]
Abandon Linux. How to install iocage to manage FreeBSD Jails
The iocage program is a python 3 piece created to manage FreeBSD Jails leveraging the underpinning ZFS file system on FreeBSD. As already explained on previous articles the FreeBSD operating system offers an OS-level virtualization system called Jails. And as described on past articles it can benefit administrators and developers alike. This is a simple […]
How to mitigate Spectre and Meltdown on an HP Proliant server with Ubuntu
As recently announced in a previous article I wanted to write a couple of guides on how to mitigate Spectre and Meltdown vulnerabilities in GNU/Linux and UNIX environments. It is always a good and I hope a standard practice to have your systems patched and if they aren’t for whatever the reason (that legacy thing […]
How to synchronize system and network time in FreeBSD
For several applications it is necessary to synchronize your server to the network time. The protocol is called Network Time Protocol (NTP) and is basically giving the correct time to the world nowadays. Reading the Wikipedia entry is very interesting. FreeBSD comes with the ntp client. To set this up you will just add the […]
How to configure the IPFW firewall on FreeBSD
Among the three possible firewalls on FreeBSD (choice is always nice) IPFW is the in-house built one. There is a default, easy way, configuration path but if one needs to build a box to act as a dedicated network appliance with packet filtering capacity fine tunning the IPFW firewall configuration is more than desirable. Before […]
How to install Webmin on FreeBSD 12
Webmin is a fantastic tool for those willing to administer UNIX or unix-like systems through a GUI interface. While the CLI interface lets any user to interact with these kind of systems to the very core and extract all the juice, there are tasks where the graphical interface makes sense and its visual and quick […]
Nmap cheatsheet
Nmap is a discovery tool used in security circles but very useful for network administrators or sysadmins. One can get information about operating systems, open ports, running apps with quite good accuracy. It can even be used in substitution to vulnerability scanners such as Nessus or OpenVAS for not very large environments, or quick audits. […]