udev – Change network card label

Several time I’ve been asked how to rename a network card label on a Linux system, this can be achieve by following the steps mentioned bellow. Stop networking service networking stop The network kernel module needs to be removed, but first you need to identify...

MySQL-ZRM and BackupPC – CentOS 7

Backups can be a tricky thing, all of us that did system administration, maintenance, or system engineering or architecture at some point had to choose a backup mechanism, that depending on the requirements can be a simple bash script that uses tar or rsync, or a...

Swap space increase on a running Linux server

If you see that your server is running out of swap you should add more RAM, nevertheless this is not always possible or maybe you need that extra amount of swap for a very specific usage.
If this is the case you just need to add some more swap to your system. There are several usage cases I’ll just cover the 2 most common ones, without LVM and no extra space available on the partition and with LVM and available space on the volume group.

megacli basic usage

When you have large deployments with thousands of SSDs and spinning disks megacli utility provides a great help by having all the features and options available in a way that can be easily scripted and therefore automated.

First impression on CentOS 7

After testing the new CentOS 7.0 here are my first impressions:
systemctl took some time to get into (learning done on my SuSE laptop distro)
I don’t really like the new FW config although I see some advantage there, if you already know iptables good enough not much to gain.

OpenVPN username/password authentication on DD-WRT

In this post I’ll be using DD-WRT build 23320 and an ASUS RT-AC66U router to establish two “always on” VPNs (using openvpn) using username / password authentication. This router supports all the new wifi protocols and in theory has over 1Gbps capability using dual band, also supports 2.4GHz and 5.0Ghz band communication. I’ve been using it with DD-WRT without any stability issues for more than 6 months now.
DD-WRT is one of my favourite linux distros, it’s specially made to work on home routers, APs and small appliances. You may download it from: http://www.dd-wrt.com and also make sure your equipment is supported by looking into the router database.