Sunday, 15 December 2019

How to Create a XFS File System on CentOS 7



A file system provides control to store, retrieve and organization of data on storage.

Friday, 6 December 2019

How to Define a Service to Add in Firewall Configuration on CentOS 7




Firewall is a network security tool that provide network level security based on a set of rules. It has controls on incoming and outgoing traffic.

How to Add a Service in Firewall Configuration on CentOS 7 (firewall-cmd)



Firewall is a network security tool that provide network level security based on a set of rules. It has controls on incoming and outgoing traffic.

How to Add a Port in Firewall Configuration on CentOS 7 (firewall-cmd)




Firewall is a network security tool that provide network level security based on a set of rules. It has controls on incoming and outgoing traffic.

How to Install Firewalld on CentOS 7



Firewall is a network security tool that provide network level security based on a set of rules. It has controls on incoming and outgoing traffic.

Tuesday, 3 December 2019

How to Install vsFTP Server on CentOS 8




vsFTP (Very Secure File Transfer Protocol) is a free and open source widely used client-server network protocol that used for transferring files between server and clients over the network.

How to Disable SE-Linux on CentOS 8




SE-Linux, or Security-Enhanced Linux, is a set of security modules which are loaded in to kernel to improve security on accessing services/files which improve security. 

Saturday, 30 November 2019

How to Mount an NFS Share on CentOS 8 Client



NFS (Network File System) is a distributed network file sharing system protocol. It is provides to share files and folders between Linux distributions over the network. Nfs-utils package needed to mount NFS share on clients as local file system.

How to Mount Windows Share on CentOS 7 using CIFS



CIFS (Common Internet File System) is an implementation of SMB and network file sharing protocol. It is used to provide shared access to files, folders and printers etc. between windows to windows and windows to Linux machines over the network.

How to Install MySQL Community Server 8 on CentOS 8



MySQL Community Server is a free and open source version of MySQL Database management System. It is widely used for database management in LAMP stack like servers and used in web applications to store and retrieve data from database.

How to Stop and Disable Firewall on CentOS 8




Firewall is a free and open source tool that provides security features to control inbound and outbound traffic. It is enabled by default in CentOS 8 Linux machines, Services and ports can be allow and block by configuring firewall service.

How to Mount/Access ISO File Contents on CentOS 7




ISO (International Organization for Standardization) format is an archive file format which mostly used to contains the complete image of an installation software’s CD or DVD, backups etc.

How to Configure iSCSI Initiator Node on CentOS 7



iSCSI (Internet Small Computer Systems Interface) is an Internet Protocol based storage networking for connecting remote storage devices over the network. It provides block-level access to storage devices. iSCSI is used to facilitate block-level data data transfer between iSCSI initiator on a client machine and target on a storage server over local area networks (LANs), wide area networks (WANs).

How to Mount an NFS Share on CentOS 7 Client



NFS (Network File System) is a distributed network file sharing system protocol. It is provides to share files and folders between Linux distributions over the network. Nfs-utils package needed to mount NFS share on clients as local file system.

Thursday, 28 November 2019

How to Install MySQL Community Server 8 on CentOS 7



MySQL Community Server is a free and open source version of MySQL Database management System. It is widely used for database management in LAMP stack like servers and used in web applications to store and retrieve data from database.

How to Configure Software RAID 5 (Distributed Parity) on CentOS 7




RAID (Redundant Array of Independent \Inexpensive Disk) is a data storage technology that combines multiple physical disk drives into a single logical volume to provide data redundancy and performance which vary depending on the RAID levels. mdadm (multiple devices admin) is a widely used tool to manage RAID on most of the Linux distributions.

How to Configure Software RAID 1 (Mirroring) on CentOS 7



RAID (Redundant Array of Independent \Inexpensive Disk) is a data storage technology that combines multiple physical disk drives into a single logical volume to provide data redundancy and performance which vary depending on the RAID levels. mdadm (multiple devices admin) is a widely used tool to manage RAID on most of the Linux distributions.

How to Configure Software RAID 0 (Striping) on CentOS 7



RAID (Redundant Array of Independent \Inexpensive Disk) is a data storage technology that combines multiple physical disk drives into a single logical volume to provide data redundancy and performance which vary depending on the RAID levels. mdadm (multiple devices admin) is a widely used tool to manage RAID on most of the Linux distributions.

Tuesday, 26 November 2019

How to pull and run Docker images in CentOS 7




Docker containers are built from Docker images which can be downloaded from Docker Hub. Docker Hub is a cloud-based registry contains Docker images either in a public or private repository.

How to Install and Configure Docker on CentOS 7



Docker is a free, open source and community tool that’s manage application processes in containers. It is a lightweight, portable, self-sufficient container and ability to automate deployment. Docker community version can be installed from its official repository.

Monday, 25 November 2019

How to Install Open Stack Client on CentOS 8 (pip Installation)




OpenStack Client is a free and open source command-line tool, which allow to manage OpenStack components i.e. Compute, Identity, Image, Object Storage and Block Storage APIs together over the network.

How to Install python2 and pip2 on CentOS 8




Python is a programming and scripting language, widely used in Linux distributions. Python deprecated in CentOS 8. Pip a package management tool and widely used for development tools installation. It can be installed using dnf install python<version> and python<versions>-pip.

How to Install OpenStack Client on CentOS 7 (pip Installation)




OpenStack Client is a free and open source command-line tool, which allow to manage OpenStack components i.e. Compute, Identity, Image, Object Storage and Block Storage APIs together over the network.

Sunday, 24 November 2019

How to Install and Configure Nginx Server on CentOS 8




Nginx is a free and open source high-performance web server. It is also used for reverse proxy, load balancer and content cache servers. Now its binary is available in CentOS 8 AppStream Repository.

How to resolve “-bash: route: command not found” on CentOS 8



By default route command is not available in CentOS8 minimal installation and other Linux distributions. route command is available by installing package net-tools. ip route show command can be used instead of route command to check listening ports and services on CentOS8 minimal installation.

How to resolve “-bash: netstat: command not found” on CentOS 8



By default netstat command is not available in CentOS8 minimal installation and other Linux distributions. netstat command is available by installing package net-tools. ss command can be used instead of netstat command to check listening ports and services on CentOS8 minimal installation.

How to Configure Chrony Time Synchronization Server on CentOS 8




Chrony is a Time Synchronization server introduced in CentOS7. It is a free and open source widely used software for time synchronization between centralized Time Server and clients over the network. Chrony rpm package and its dependencies are available in CentOS8 base repository.

How to resolve “-bash: ifconfig: command not found” on CentOS 8



By default ifconfig command is not available in CentOS8 minimal installation and other Linux distributions. ifconfig command is available by installing package net-tools. ip a command can be used instead of ifconfig command on CentOS8 minimal installation.

How to Rename Network Interface Name on CentOS 8



In CentOS 7 and CentOS 8, a new NIC naming scheme is the predictable naming rule is adopted by default like ens192, enp3s0, eth0 and so on. To disable the predictable naming rule pass "net.ifnames=0" and biosdevname=0” kernel parameter during boot.

Saturday, 23 November 2019

How to Disable Network Manager on CentOS 8




The Network Manager Service is enabled by default on CentOS 8 and all the network services are managed by Network Manager. Network Manager is not suitable for advanced networking setup, such as configuring Network Bridge, aliases and interface name conversions etc. Alternatively, add "NM_CONTROLLED=no" directive in the network configuration files instead of disabling Network Manager.

Friday, 22 November 2019

How to Configure Password Less Authentication on CentOS 7



In some certain reason, password less authentication is require on remote machine which helps to access the remote machine without entering the password for login, deployment and management purpose.

How to Install GFS2 (Global File System 2) Packages on CentOS 7




GFS2 (Global File System 2) is a shared disk file system and interfacing directly with the kernel VFS (Virtual File System) layer. GFS2 file system allows concurrent access to local and multiple cluster nodes.

How to Resolve "Permission denied (publickey,gssapi-keyex,gssapi-with-mic)" Error on CentOS 7



In most of cloud images, password authentication login method is disabled in Open SSH Configuration and can be logged in using SSH private key only. Following error messages will appear while coping ssh on remote server and also will get error when login on the server using password.

How to Resolve “No package iperf available.” on CentOS 7




Mostly the massage “No package iperf available” will appears when the package is not available in CentOS 7 Base/default repositories and the massages will display like below:

How to Install and Configure Ceph Storage on CentOS 7



Ceph Storage is a free and open source widely used software defined storage solution which provides file system storage, object storage and block level centralize storage.

Sunday, 17 November 2019

How to Configure iSCSI Target with Two LUNs on CentOS 7 (Using HDD Partitions)



iSCSI (Internet Small Computer Systems Interface) is an Internet Protocol based storage networking for connecting remote storage devices over the network. It provides block-level access to storage devices. iSCSI is used to facilitate block-level data transfer between iSCSI initiator on a client machine and target on a storage server over local area networks (LANs), wide area networks (WANs).

Saturday, 16 November 2019

How to Configure iSCSI Target and Initiator on CentOS 8



iSCSI (Internet Small Computer Systems Interface) is an Internet Protocol based storage networking for connecting remote storage devices over the network. It provides block-level access to storage devices. iSCSI is used to facilitate block-level data transfer between iSCSI initiator on a client machine and target on a storage server over local area networks (LANs), wide area networks (WANs).

Sunday, 10 November 2019

How to Install XRDP Remote Desktop Server on CentOS 8



XRDP is an Open Source Remote Desktop Protocol Server, which is allowing users to take remote desktop of Linux Operating System from RDP clients. XRDP uses RSA Public Key and Private Key encryption to transfer data over the network.

How to Install Gnome GUI on CentOS 8 Using YUM Group Install



CentOS 8 and many Linux distributions have options to install minimal, GUI and others and minimal installation restrict resource utilization. However if minimal installation done while installation and GUI can be installed later.

How to Increase Swap Memory in Centos 7 (Using HDD Partition)




Linux distributions has the facility to reserve some amount of disk space to use as virtual memory when the amount of physical memory (RAM) is full. Swapping is a method when the RAM is fully utilized, inactive pages in the memory are moved to the swap space from the RAM to swap space.

Saturday, 9 November 2019

How to Install Ccrypt on CentOS 8 Using RPM Package



Ccrypt is a command line utility for encryption and decryption of files and streams in Linux [CentOS 8]. The Ccrypt utility is not available in CentOS 8 base repository.

How to Install Postfix Mail Server on CentOS 8 Minimal




Postfix is a free and open source widely used mail server for Linux distributions. It is available in base repository on most of the latest Linux distributions.

How to Install Nagios Core Server on CentOS 7



Nagios Core is free and open source widely used monitoring tool which can be used for monitoring Linux servers, Windows servers, Network devices and other applications. Nagios provides alerting services (SMS, Email etc.) for abnormal utilization and issues for Attributes CPU load, Memory usage, Disk usage, Logged in users, Running processes etc. and Services HTTP, FTP, SSH, SMTP, POP3, SNMP etc.

How to Increase Swap Memory in CentOS 7 (Using Swap File)



Linux distributions has the facility to reserve some amount of disk space to use as virtual memory when the amount of physical memory (RAM) is full. Swapping is a method when the RAM is fully utilized, inactive pages in the memory are moved to the swap space from the RAM to swap space.

Friday, 1 November 2019

How to Changing/Reset the root password on the CentOS 7 qcow2 Image (virt-customize)



"virt-customize" provide a feature to customize a file system and its configuration data of a qcow2 format images.

How to Configure NFS File Sharing Server on CentOS 7




NFS (Network File System) is a distributed network file sharing system protocol. It is provides to share files and folders between Linux distributions over the network.

How to Set root Password of CentOS 7 Cloud Image (guestfish)




Most of the cloud images protect by disabling root password and Disabling Remote Root and Other users login using their passwords. By default "guestfish" is an interactive shell that provides directory access the guest virtual machine file system access.

Wednesday, 30 October 2019

How to Install Screen utility in CentOS 8



Screen utility allows running multi-tasking environment and keeping processes running in the background. By default, package is not available in CentOS distribution.

How to Disable IPv6 (Internet Protocol version 6) on CentOS 8



IPv6 (Internet Protocol version 6) is the latest version of the Internet Protocol (IP) that provides an identification and location for internet devices on networks and provides a larger IP addressing scheme for IoT (Internet of Device). IPv6 is looks like as below on CentOS:

Tuesday, 29 October 2019

How to Install PHP 7.3 Latest Version on CentOS 7



PHP is free and open source programming language. It is widely used Linux based system for web application developments. PHP 5.4.xx packages are available in CentOS 7 base/default repositories which are old versions and about to end of life. 

How to Install REMI Repository on CentOS 7



REMI Repository is a third-party repository that provides the latest versions of software for Enterprise Linux, CentOS and for other clones. The REMI repository works along with EPEL repository to resolve any dependency for packages.

How to Install PHP 5.4 on CentOS 7



PHP is free and open source programming language. It is widely used Linux based system to write application. PHP package is available in CentOS 7 Base/default repositories:

Monday, 28 October 2019

How to Resolve “No package iperf available.” on CentOS 7



Mostly the massage “No package iperf available” will appears when the package is not available in CentOS 7 Base/default repositories and the massages will display like below:

Sunday, 20 October 2019

How to install and configure Samba Server on CentOS 7



Samba Server is an open source file sharing server. It allows to access files, folders and printers between Linux server and windows client.

How to Create Local YUM repository on CentOS 7



YUM (YellowDog Updater Modified) is a package management tool for RPM based Linux system that helps to install, uninstall, and update packages local and over the network. YUM resolve all dependency and install the package with all dependencies.

How to Configure 3 Nodes High Availability Cluster with Pacemaker and CoroSync on CentOS 7



High Availability (HA) Cluster provides the continued availability of services without failure for a long period of time. If one of the cluster nodes fails, the pacemaker service will start the services on another node. Pacemaker and CoroSync are open source and widely used software for service high availability in production environments.

Sunday, 13 October 2019

How to configure Apache Web Server 2 Nodes High Availability Cluster with Pacemaker and Corosync on CentOS 7



High Availability (HA) Cluster (active-passive) provides the continued availability of services without failure for a long period of time. If one of the cluster nodes fails, the pacemaker service will start the services on another node. Pacemaker and Corosync are open source and widely used software for service high availability in production.

How to Install and Configure Postfix Server on CentOS 7



Apache is most popular and open source web server to server html, php and others. It released by Apache foundation under GNU license. The Apache binary is available in CentOS 7 default repository.

How to Install Apache/httpd Web Server on CentOS 7



Apache is most popular and open source web server to server html, php and others. It released by Apache foundation under GNU license. The Apache binary is available in CentOS 7 default repository.

Tuesday, 8 October 2019

How to Install and Configure VNC Server on CentOS 7



VNC (Virtual Network Computing) server is a utility which provides remote desktop accessibility over the network.

How to Resolve “Warning: RPMDB altered outside of yum” CentOS 7



The message “Warning: RPMDB altered outside of yum” displayed when the yum command is not finished completely or interrupted while running any yum transaction and rpmdb does not completed the rpm database editing.

How to Configure 2 Nodes High Availability Cluster with Pacemaker and Corosync on CentOS 7



High Availability (HA) Cluster provides the continued availability of services without failure for a long period of time. If one of the cluster nodes fails, the pacemaker service will start the services on another node. Pacemaker and Corosync are open source and widely used software for service high availability in production environments.

How to Enable EL repository in CentOS 7



The EL repository is an additional RPM repository for Enterprise Linux. ELRepo supports Red Hat Enterprise Linux and its derivatives Scientific Linux, CentOS and its other distributions that provides hardware related file system drivers, graphics drivers, network drivers, sound drivers, webcam and video driver’s related packages.

Wednesday, 2 October 2019

How to configure EPEL repository on CentOS 8



The EPEL repository is an additional package repository that provides useful software packages that are not included in the official CentOS 8 repositories and easy access to install packages for commonly used software.

How to resolve wget: command not found in CentOS 8



wget command: It is a command-line utility and used to downloads files over a network. wget is a free utility to download files and available most of the Linux distributions.

Sunday, 29 September 2019

How to Install CentOS 8.0 Minimal Step by Step



The CentOS Project is recently released CentOS 8.0 for Linux users. It is a new community version of RHEL 8 and has many new features such as multiple versions of packages are available in CentOS 8 Base repository and App Stream for the additional user space applications.

How to change Hardware Clock date and time Using hwclock



The hardware clock also known as BIOS clock. It is independent operating system clock and it works even when shut down the system. hwclock utility is used to check current time of hardware clock and adjust the hardware clock time.

Saturday, 28 September 2019

How to Enable Software Collections (SCL) yum repository on CentOS 7



The Software Collection is an additional package repository that allow users to easily and safely install most recent versions of applications and configure online environments without compromising the performance of the existing system. It is reliable, community edition and provides useful software packages that are not included in the official CentOS 7 default repositories.

How to install and configure Tomcat 9 on CentOS 7/RHEL 7



Apache Tomcat open source and free binary deployed by Apache Foundation. It is commonly used to run Java programs/applications for web and servlet container hosting.

How to install Java8/jdk1.8 using yum command on Centos 7



By default Java packages are available in CentOS 7 base repositories and it can be installed using yum command. This article describes how to install Java8/jdk1.8 using yum command on CentOS 7.

Sunday, 22 September 2019

How to install and configure Open vSwitch with NIC bonding on CentOS 7



Open vSwitch is a multi layer software switch which is free and open source software released under Apache 2 license. In this tutorial we are going to setup Open vSwitch with NIC bonding. NIC Bonding enables two or more network interfaces to act as one interface, to provide higher data rates and as well as link fail over.

Saturday, 21 September 2019

How to use yum command to update and patch Centos 7



Centos 7 is a major release of Centos release. Yum command can used to check latest updates and install security updates and patches on Centos systems from internet. Since, Centos 7 is major release of Centos the yum command can upgrade to the latest minor release (Centos 7.7).

Saturday, 14 September 2019

How to check routing table on CentOS 7



The routing table is displays the different sub nets and their routes details. Also the table provides information about default route and other routes and their matrices. This article describes various commands that displays routing table in CentOS 7.

How to resolve “-bash: /usr/sbin/ifconfig: No such file or directory” on CentOS 7



The ifconfig command deprecated in CentOS 7 minimal installation and most of the Linux distributions. The ip a command can used instead of ifconfig command. The following steps describes installation of ifconfig command on CentOS 7.

How to resolve “-bash: route: command not found” on CentOS 7



The route command deprecated in CentOS 7 minimal installation and most of the Linux distributions. The ip command can used instead of route command. The following steps describes installation of route command on CentOS 7.

Saturday, 31 August 2019

How to Install MariaDB Database on CentOS 7



MariaDB is a popular open-source database and community-developed fork of MySQL. MariaDB database, It is widely used for database management in LAMP stack like servers.

How to disable IPv6 on CentOS 7



Internet Protocol version 6 (IPv6) is the latest version of the Internet Protocol (IP) that provides an identification and location for Internet of devices on networks and provides a larger IP addressing scheme for Internet of devices.

Tuesday, 27 August 2019

How to configure Multipating with iSCSI Target in centos 7



DM-Multipath stands for “Device Mapper Multipathing”. It is a basic multipating for data transferring in Linux systems. Mostly it is used for redundancy and to improve the input/output performance.

Sunday, 25 August 2019

How to Install and Configure iSCSI Target on CentOS 7



iSCSI (Internet Small Computer Systems Interface) is an Internet Protocol based storage networking for connecting remote storage devices over the network. It provides block-level access to storage devices. iSCSI is used to facilitate block-level data data transfer between iSCSI initiator on a client machine and target on a storage server over local area networks (LANs), wide area networks (WANs).

Saturday, 24 August 2019

How to Install Centos 7 Minimal Step by Step



This article describes the minimal installation of Centos 7. Here we are using Centos 7.6 image for installation.

Saturday, 22 June 2019

How to install XAMPP Server on CentOS 7



XAMPP is an open source multi-platform software stack. It contains Apache, MariaDB, PHP and Perl and provides a suitable environment for testing Apache MYSQL, PHP and Perl projects.

Saturday, 15 June 2019

How to Setup NIC bonding Interface Using nmcli on CentOS 7



NIC Bonding enables two or more network interfaces to act as one interface, to provide higher data rates and as well as link failover. Linux kernel features that allows aggregating multiple interfaces. This is a great way of achieving redundancy to a server. If one physical NIC is down or unplugged, it will automatically move resource to other NIC card.

Sunday, 9 June 2019

How to install and configure Open vSwitch on CentOS 7 Server



Open vSwitch is a multilayer software switch which is free and open source software released under Apache 2 license. Open vSwitch is well suited and used to manage the traffic between virtual machines and physical or logical networks. Open vSwitch supports multiple Linux-based virtualization and overlay techniques.

Saturday, 8 June 2019

How to monitory SSL Certificate expiry With Nagios



Nagios plugin “check_http” provides SSL Certificate monitoring to check certificates expiration dates and Nagios generate alerts when SSL certificates near their expiration date. So the same can renew their certificates before problems occur.

Wednesday, 22 May 2019

How to Create a Linux Network Bridge Using nmcli tool on CentOS 7



A Linux bridge is used to connect two or more network segments. It is commonly used in Virtualization to pass multiple VLANs through a physical network.

Saturday, 11 May 2019

How to Install Jenkins on Cent OS 7



Jenkins is a popular free and open source, Java-based automation tool that provide continues integration and continuous delivery.  Its code is written in Java. It provides the feature of continues development, deployment, and automation.

Saturday, 4 May 2019

How to install Java8/jdk1.8 in Centos7 using YUM



Step 1: Install OpenJDK 8 JRE and JDK packages using the yum package manager. Java 8 binaries are available in Centos 7 repository. Run the following command to install the packages:

Thursday, 7 March 2019

How to install and configure Chrony/NTP Configuration



Chrony is available in default repository of Centos 7 and RHEL 7.

Wednesday, 20 February 2019

How to disable consistent network device naming in CentOS 7



Step 1: Insert the following line in grub configuration file /etc/default/grub: