Write Your own Custom Plugin on check_mk

The check_mk is a open source monitoring solution with hundreds of checks which enables you to monitor your IT infrastructure. Besides it allows you to configure most of your monitor related activities from the graphical interface called “WATO”. Most of the time it automatically discover the system, once it is added to the check_mk inventory. […]

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Connect KVM over GRE

Hi Folks, As you may know, Libvirt virtual network switches operates in NAT mode in default (IP Masquerading rather than SNAT or DNAT). In this mode Virtual guests can communicate outside world. But, Computers external to the host can’t initiate communications to the guests inside, when the virtual network switch is operating in NAT mode. […]

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DRBD(without clustering)

Do you need transparent, real-time replication of block devices without the need for specialty hardware without paying anything ? If your answer is YES. DRBD is your solution. DRBD is a distributed replicated storage system for the Linux platform. It is implemented as a kernel driver, several userspace management applications, and some shell scripts. DRBD […]

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Checking Connection without Telnet

Some of the minimal Linux distributions have no telnet client utility or similar utilities such as nc,ncat unless you install it. Most of time we need to do troubleshooting to check connection if  server/service is accessible. Do not worry–You still have mechanism inside the Linux kernel without installing above utilities. Take a look at below examples […]

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Minimizing Docker Images with Multistage

When you build your own  docker image from Dockerfile,  each instruction in Dockerfile creates a new layer to your base image with its all dependencies so that even your very tiny application image size may be in 1GiB  size and it is not desirable in the production environment to be such a big size due to […]

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Building RHEL7 Cluster Part-I

Hello Folks, It has been long time, I could not create any post about the clustering with RHEL7. It uses Pacemaker as a high-availability cluster resource manager. In this post, It will be used two-node cluster. Each of the node has been configured to resolve the hostnames into the IP addresses. Also, each node has […]

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Sorting by Specific Column in PowerShell

Hello Folks, I needed a script in Poweshell which sorts the data by specific column. I wanted to share it on my blog as I do not see much examples over the Internet. Let’s say you have data as below and you want to sort this data by specific column. In this example I sort […]

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Solutions of NATAS 1-15

Hello Folks, In this post, I will share with you the solutions of Natas challenges from one to fifteen. It is strongly recommended not to look at the solutions without cogitating. Natas0: Username and password have been already provided for Natas0. URL: http://natas0.natas.labs.overthewire.org natas0/natas0 Solution: Login the page with the credential natas0/natas0. On Chrome Browser right-click […]

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Aruba VAN SDN Controller (invalid user & password combination specified!)

Hello, In this post, I will give the resolution of Invalid user & password combination specified error by the Aruba VAN SDN Controller after fresh installation from the deb. package Ubuntu version for the SDN Controller. tesla@hpcontroller:~$ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 14.04.5 LTS Release: 14.04 Codename: trusty […]

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