Firewall CentOS 7 now uses FirewallD, which is not bad, but I don’t think it’s mature enough. So to just disable it and get back to the classic iptables service there are some steps: systemctl stop firewalld systemctl disable firewalld yum -y install iptables-services systemctl enable iptables systemctl restart iptables If you run dual stack, […]
On a typical Linux mail server mail is stored on the disk either using one big file in /var/mai/%user either in one Maildir in users’s home folder. This Maildir usually contains one small file for each mail stored on your server and some indexing information etc. In this setup, because users are stored on a […]
This mail server will use Postfix as a MTA, Dovecot as an LDA, IMAP/POP Server, and MariaDB(MySQL) to store user login information. It will also use PostfixAdmin web interface to manage domain, users and mail administrators information. HTTPD To run the web administration interface and the Webmail we need to have an HTTP server running. […]
First thing is to chose the Distro. For this install I chose CentOS 7, basically a RHEL clone, version 7 is the latest one. Download You can download the minimal install ISO from here. Then you need to burn this ISO on a CD or on a memory stick in order to be able to […]
I run this website on a physical server that i rent. Recently I wanted to run on the same server a virtual machine, with a different OS, with a public IP address(I use KVM for that, as there’s nothing to really change on the physical server’s OS and performance-wise it’s more than OK). The way […]
Well, on a high-traffic mail server we need to follow the server log, to look for possible issues. The “tail -f” method might just not be as good as we would want, text is going up too fast and web just can’t read that fast. A solution to that is multitail. On CentOS/RHEL we would […]
Let’s say you’re on a news website for instance bbc.co.uk, that you read a lot, but each time you look on the website you can’t tell if you already visited that portion of the website or not. Let’s say you still have a chance, there’s a Firefox and Chrome add-on called Stylish. First you need […]
On Debian/Ubuntu we would need to search for installed kernel packages, something like this: root@server:~# dpkg –list |grep linux-image ii linux-image-3.2.0-23-generic 3.2.0-23.36 Linux kernel image for version 3.2.0 on 64 bit x86 SMP ii linux-image-3.2.0-56-generic 3.2.0-56.86 Linux kernel image for version 3.2.0 on 64 bit x86 SMP ii linux-image-3.2.0-57-generic 3.2.0-57.87 Linux kernel image for version […]
Well, in EL6 when we wanted to change Apache’s MPMs we would edit /etc/sysconfig/httpd and set the HTTPD variable with the binary needed.It looks something like: HTTPD=/usr/sbin/httpd.worker To see the available options we could type the following command: [root@server ~]# ls /usr/sbin/httpd* /usr/sbin/httpd /usr/sbin/httpd.event /usr/sbin/httpd.worker The simple httpd binary uses the Prefork MPM, httpd.worker is […]
First of all we need to deactivate FirewallD systemctl disable firewalld.service Then we install the package called iptables-services yum install iptables-services edit /etc/sysconfig/iptables then start classic iptables and make it load on each reboot systemctl start iptables.service systemctl enable iptables