Install Mariadb on CentOS 7

MariaDB is an open-source relational database management system, backward compatible, binary drop-in replacement of MySQL. It is developed by some of the original developers of the MySQL and by many people in the community. With the release of CentOS 7, MySQL was replaced with MariaDB as the default database system.

If you, for any reason need to install MySQL, check the How to Install MySQL on CentOS 7 tutorial. If your application does not have any specific requirements, you should stick with MariaDB, the default database system in CentOS 7.

In this tutorial we will show you how to install the latest version of MariaDB on CentOS 7 using the official MariaDB repositories.

Prerequisites

Make sure you are logged in as a user with sudo privileges before proceeding with the tutorial.

Install MariaDB 5.5 on CentOS 7: The version of the MariaDB server provided in default CentOS repositories is version 5.5. This is not the latest version though, but it is quite stable.

Follow the steps below to install and secure MariaDB 5.5 on CentOS 7:

Install the MariaDB package using the yum package manager:

sudo yum install mariadb-server

Press y when prompted to proceed with the installation. Once the installation is complete, start the MariaDB service and enable it to start on boot using the following commands:

sudo systemctl start mariadbsudo systemctl enable mariadb

To verify that the installation was successful, check the MariaDB service status by typing:

sudo systemctl status mariadb

The output should show that the service is active and running: Continue reading “Install Mariadb on CentOS 7” »

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Reinstall VirtualBox on Ubuntu & CentOS

For Ubuntu

To remove virtualbox

sudo dpkg --list virtualbox-*
sudo apt autoremove --purge virtualbox*
dpkg -l virtualbox* | grep ^i

Remove all PPAs from sources.list and source.list.d directory

mkdir ~/apt-tmp
sudo mv /etc/apt/sources.list.d/* ~/apt-tmp

Make sure there is nothing except official repositories sources in /etc/sources.list. And update your sources:

sudo apt update

Now we can search to see which versions are available to install:

apt-cache madison virtualbox | grep -iv sources

Which produces an output like this:

virtualbox | 5.0.32-dfsg-0ubuntu1.16.04.2 | http://mirrors.kernel.org/ubuntu xenial-updates/multiverse amd64 Packages
virtualbox | 5.0.18-dfsg-2build1 | http://mirrors.kernel.org/ubuntu xenial/multiverse amd64 Packages

Then I would install the last version mentioned in xenial-updates: Continue reading “Reinstall VirtualBox on Ubuntu & CentOS” »

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Disable FirewallD and Enable Iptables on CentOS 7

Download and Install the Iptables Service

To begin your server’s transition, you need to download and install the iptables-service package from the CentOS repositories. Download and install the service files by typing:

sudo yum install iptables-services

This will download and install the systemd scripts used to manage the iptables service. It will also write some default iptables and ip6tables configuration files to the /etc/sysconfig directory.

Construct your Iptables Firewall Rules

Next, you need to construct your iptables firewall rules by modifying the /etc/sysconfig/iptables and /etc/sysconfig/ip6tables files. These files hold the rules that will be read and applied when we start the iptables service.

How you construct your firewall rules depends on whether the system-config-firewall process is installed and being used to manage these files. Check the top of the /etc/sysconfig/iptables file to see whether it recommends against manual editing or not:

sudo head -2 /etc/sysconfig/iptables

If the output looks like this, feel free to manually edit the /etc/sysconfig/iptables and /etc/sysconfig/ip6tables files to implement the policies for your iptables firewall:

output
# sample configuration for iptables service
# you can edit this manually or use system-config-firewall

Open and edit the files with sudo privileges to add your rules:

sudo nano /etc/sysconfig/iptables
sudo nano /etc/sysconfig/ip6tables

After you’ve made your rules, you can test your IPv4 and IPv6 rules using these commands:

sudo sh -c 'iptables-restore -t < /etc/sysconfig/iptables'
sudo sh -c 'ip6tables-restore -t < /etc/sysconfig/ip6tables'

If, on the other hand, the output from examining the /etc/sysconfig/iptables file looks like this, you should not manually edit the file: Continue reading “Disable FirewallD and Enable Iptables on CentOS 7” »

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Zimbra 8.8 on CentOS 7

Before we proceed with Zimbra Collaboration Suite installation process, first login to your server console with root privileges and install the following packages:

# yum -y install unzip net-tools sysstat openssh-clients perl-core libaio nmap-ncat libstdc++.so.6 perl perl-core ntpl nmap sudo libidn gmp libaio libstdc++ unzip sqlite dnsmasq

Next, issue getenforce command to check if Selinux in enabled on your machine. In case the policy is set to Enforced disable it by issuing the below commands:

# getenforce
# setenforce 0
# getenforce

To completely disable Selinux on CentOS, open /etc/selinux/config file with a text editor and set the line SELINUX to disabled.

Assure that wget system utility is also installed on your system by issuing the following command:

# yum install wget

In order for Zimbra to function correctly you must set the local machine hostname and FQDN to point to your server IP Address by running the below commands from root account:

# hostnamectl set-hostname mail
# echo "192.168.0.14 mail.centos7.lan mail " >> /etc/hosts
# cat /etc/hosts

Replace the system hostname and FQDN values accordingly in order to match your own domain settings. Test the hostname and FQDN values by issuing the ping command against both records. Continue reading “Zimbra 8.8 on CentOS 7” »

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Install VirtualBox on Centos 6 / 7

Step 1 – Add Required Yum Repositories

Firstly you are required to add VirtualBox yum repository in your system. Download repository file from its official site and place it under at /etc/yum.repos.d/virtualbox.repo .First navigate to /etc/yum.repos.d/ directory and use one of below commands as per your operating system.

cd /etc/yum.repos.d/
wget http://download.virtualbox.org/virtualbox/rpm/rhel/virtualbox.repo

The CentOS and RedHat users also required to add EPEL yum repository using one of the following commands.

### On CentOS/RHEL 7 ### 
rpm -Uvh http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
### On CentOS/RHEL 6 ### 
rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

Step 2 – Install Required Packages

Before installing VirtualBox make sure to install all required packages to run VirtualBox like kernel-headers, kernel-devels etc. Use the following command to install the required packages. Continue reading “Install VirtualBox on Centos 6 / 7” »

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Installing NTP Service and change timezone in CentOS 6 / CentOS 7

Let’s install NTP service first:

yum install ntp

Configure NTP services by updating the following section (only if appropriate):

nano /etc/ntp.conf

And by commenting on the sections:

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#server 0.centos.pool.ntp.org iburst
#server 1.centos.pool.ntp.org iburst
#server 2.centos.pool.ntp.org iburst
#server 3.centos.pool.ntp.org iburst

In my case I used the following National Time Server of Bangladesh:

server bsti1.time.gov.bd
server bsti2.time.gov.bd

save and restart the ntp service.

Change Timezone on a CentOS 6 and 7

How do I see the current time zone on CentOS Linux?

Type the date command or the ls command:

$ date
$ ls -l /etc/localtime

Another option is to type the following command on systemd based distro such as CentOS 7 to see timezone along with the grep command and timedatectl command: Continue reading “Installing NTP Service and change timezone in CentOS 6 / CentOS 7” »

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Install and integrate DKIM with OpenDKIM and Postfix on a CentOS 6

UPDATE THE SYSTEM

Before going any further, make sure you’re in a screen session and your system is fully up-to-date by running:

## screen -U -S opendkim-screen
## yum update

ENABLE EPEL REPOSITORY

OpenDKIM is available in the EPEL repository, so we need to enable it on the system before we can install OpenDKIM

## wget -P /tmp http://mirror.pnl.gov/epel/6/i386/epel-release-6-8.noarch.rpm
## rpm -Uvh /tmp/epel-release-6-8.noarch.rpm
## rm -f /tmp/epel-release-6-8.noarch.rpm

INSTALL OPENDKIM

Install the package using yum:

## yum install opendkim

CONFIGURE OPENDKIM

Next thing to do is to configure OpenDKIM. Its main configuration file is located in /etc/opendkim.conf, so before making any changes create a backup and add/edit the following: Continue reading “Install and integrate DKIM with OpenDKIM and Postfix on a CentOS 6” »

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Apache Virtual Hosts on CentOS

Step One— Create a New Directory

The first step in creating a virtual host is to a create a directory where we will keep the new website’s information.

This location will be your Document Root in the Apache virtual configuration file later on. By adding a -p to the line of code, the command automatically generates all the parents for the new directory.

sudo mkdir -p /var/www/example.com/public_html

You will need to designate an actual DNS approved domain, or an IP address, to test that a virtual host is working. In this tutorial we will use example.com as a placeholder for a correct domain name.

However, should you want to use an unapproved domain name to test the process you will find information on how to make it work on your local computer in Step Six.

Step Two—Grant Permissions

We need to grant ownership of the directory to the user, instead of just keeping it on the root system.

sudo chown -R apache:apache /var/www/example.com/public_html

Additionally, it is important to make sure that everyone will be able to read our new files.

sudo chmod 755 /var/www

Now you are all done with permissions. Continue reading “Apache Virtual Hosts on CentOS” »

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Install Netdata on CentOS 6

Installing Netdata

[root@linuxhelp Desktop]# yum install zlib-devel libuuid-devel libmnl-devel gcc make git autoconf autogen automake pkgconfig -y
Loaded plugins: fastestmirror, refresh-packagekit, security
Setting up Install Process
Determining fastest mirrors
.
.
perl-Error.noarch 1:0.17015-4.el6 perl-Git.noarch 0:1.7.1-9.el6_9 
ppl.x86_64 0:0.10.2-11.el6

Complete!

It doesn’t end with that, you should also install additional packages. Run the following command for the same purpose. Continue reading “Install Netdata on CentOS 6” »

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