Skip to main content

Posts

Understanding Linux Cluster

Hello Thanks for visiting RvKmR's blogs. So, What means of clusters and why we need them. Cluster is set of servers or say computers working together to achieve single goal or a task. Now you may have idea why we need cluster.  Types of Cluster: High Availability Cluster / HA Cluster  HA Cluster again grouped in two types. Active-Active Cluster Active-Passive Cluster In Active-Active Cluster Service is running on all nodes in cluster. That means all nodes serving independently. In Active-Passive Cluster Service is running on one of node from cluster and other nodes in passive state. If primary node fails then only other node in cluster will start service.   Storage Cluster In this cluster type, all members provides a single cluster file system that can be accessed by different servers. These file system can be used to read-write data simultaneously. EX: GFS2  OK, Then what is High Availability. This type of cluster provides high availability of serv
Recent posts

Ansible for Microsoft's Windows

Hello Thanks for visiting RvKmR's blogs T oday we are discussing managing Microsoft Windows machines with Ansible. We know that managing Linux machines with Ansible is quite common nowadays. but managing windows machines with Ansible is quite new. SSH service is used to manage Linux machine and for windows WinRM. Please check more details about WinRM here . L ets checkout steps to configure WINRM for ansible. Below are requirements for WINRM configuration on target windows machine. Admin Credentials of target windows machine. Stop firewall on target windows machine. Powershell version 3.0 and .net framework 4.0 Let's start configuring Windows machine: I am considering you have administrator account credentials with you. Open Firewall in windows machines and turn of it or allow port 5985 and 5986. Update Powershell and .Net Framework with below commands on PowerShell. $url ="https://raw.githubusercontent.com/jborean93/ansible

IT Infrastructure Monitoring

Hello, Thanks for visiting RvKmR.blogspot.in IT Infrastructure monitoring its not just words, it means a lot in the information technology world. I expect an IT professional knows what it means. In a simple word, I can say Compute, Application, and network, etc. OK, let's start why we need IT infrastructure monitoring. Monitoring IT infrastructure allows us to take preemptive action to be undertaken towards a potential problem before they affect your business. OR at least reduce time to restore your infrastructure as soon as an incident occurs. Further monitoring of IT infrastructure is divided into two categories Agent-based and agentless. An agent is a software or script installed on machines that to be monitored so that it will send information to monitoring systems. Having an agent inside the machine uses system resources, which in turn raises maintenance cost. Whereas the agentless tool is little or no impact on monitored machines as an agent is not installed on

Collect ansible Inventory from directories

Hello Thanks for visiting RvKmR.blogspot.in In this blog post, I am explaining about ansible inventory. While working with ansible we need to provide inventory to ansible commands. We may have ansible inventory structure as like below. There can be some tasks that you wish to perform on all of the inventory. But it is difficult to collect or merge these into one file. Lets do it ... level1/ ├── level2-0 │   └── inventory │       ├── server01 │       ├── server02 │       ├── server03 │       ├── server04 │       ├── server05 │       ├── server06 │       ├── server07 │       ├── server08 │       ├── server09 │       └── server10 ├── level2-1 │   └── inventory │       ├── server11 │       ├── server12 │       ├── server13 │       ├── server14 │       ├── server15 │       ├── server16 │       ├── server17 │       ├── server18 │       ├── server19 │       └── server20 └── level2-2     └── inventory         ├── server21         ├── server22         ├── server23         ├── serve

Passwordless ssh login

Hello, Thanks for visiting RvKmR.blogspot.in In this blog post, I am explaining about configuring passwordless ssh login. I setup two vms on vagrant environment, name and IP address of respective machines is listed below. I am using image "Ubuntu 14.04.5 LTS " alpha-ubuntu      10.0.0.10 beta-ubuntu        10.0.0.11 At this stage I am logged in to machine alpha-ubuntu. When I login from alpha-ubuntu to beta-ubuntu, it ll ask for password for respective logging in user. lets check it out. vagrant@alpha-ubuntu:~$ ssh beta-ubuntu The authenticity of host 'beta-ubuntu (10.0.0.11)' can't be established. ECDSA key fingerprint is 06:8d:d6:6d:a1:07:8e:19:2d:1a:2e:5c:b8:0a:0b:f5. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'beta-ubuntu' (ECDSA) to the list of known hosts. vagrant@beta-ubuntu's password: Welcome to Ubuntu 14.04.5 LTS (GNU/Linux 3.13.0-129-generic x86_64) Last login: Sun Oct 29 09:38

Wheel Users in Linux

Hello, Thanks for visiting RvKmR.blogspot.in In this blog post, I am explaining about Wheel users in Linux. Red Hat release that I am working on is as below.  [ravi@localhost vagrant]$ cat /etc/redhat-release CentOS release 6.9 (Final) An Linux system can have many users like System users, normal users, and admin (root) user. Its common sens that we have is not to share root user credentials with other user, but here is case that we wish to run administrative command by normal user. In that case we need to aware about wheel users group. Let's first understand what is wheel user in Linux and why we needed it. Wheel is one of Linux user group that allow members of that group to run administrative commands those need root access of system, Wheel user facilitate to do that with sudo (superuser do ) privileges. Lets do it on terminal : Add an user and set password [root@localhost vagrant]# useradd ravi [root@localhost vagrant]# passwd rav

Installing Jenkins in ubuntu

Hello, Thanks for visiting RvKmR.blogspot.in In this blog post, I am explaining about installing Jenkins in the ubunut system. Ubuntu release that I am working on is as below DISTRIB_ID=Ubuntu DISTRIB_RELEASE=17.04 DISTRIB_CODENAME=zesty DISTRIB_DESCRIPTION="Ubuntu 17.04" I will explain working on Jenkins in another post, for now, we will discuss how to install Jenkins in Ubuntu system. To run Jenkins successfully we need a web server. I am familiar with nginx, so I am going with it. Jenkins by default works on 8080 port. Install Jenkins with below command  sudo apt-get install nginx Jenkins is written in Java, so we need Java to be installed on our system. Adding repo to install jdk sudo add-apt-repository ppa : openjdk -r/ ppa sudo apt-get update Install jdk now. sudo apt-get install openjdk -8- jdk Add Jenkins key and update source list to install Jenkins. wget https://jenkins-ci.org/debian/jenkins-ci.org.key sudo apt-key add jenki