Whenever you apply an install/update/remove any package or packages Ubuntu log the changes happened to packages in its default file /var/log/dpkg.log. If you do listing to /var/log/ path (below is the command) you may find numbers of uncompressed and compressed dpkg.log files it depends on what type of log rotate policy is configure in file…
Category: OpenSource
Simple way to configure Ngnix High Availability Web Server with Pacemaker and Corosync on CentOS7
Pacemaker is an open source cluster manager software which provide high availability of resources or services in CentOS 7 or RHEL 7 Linux. It has feature of scalable and advanced HA Cluster Manager. This HA cluster manager distributed by ClusterLabs. Corosync is the core of Pacemaker Cluster Manager as it is responsible for generating heartbeat…
How to recover “rpmdb open failed” error in RHEL or Centos Linux
You are updating the system through yum command and suddenly power goes down or what happen if yum process is accidentally killed. Post this situation when you tried to update the system again with yum command now you are getting below error message related to rpmdb: error: rpmdb: BDB0113 Thread/process 2196/139984719730496 failed: BDB1507 Thread died…
Docker and Containers New Buzzwords.
Docker is a container management service. The Docker keyword coined in DevOps for develop, ship and run anywhere why it is so because it enable the developers to easily develop the applications, ship the application into containers and later it can be deployed anywhere. The Docker was released in March 2013 but has become buzzword…
What is OpenFlow? How it works in SDN?
OpenFlow is a standard protocol of SDN which assist SDN Controller to communicate directly with the forwarding plane of network devices such as switches and routers, both physical and virtual (hypervisor-based), so it can better adapt to changing business requirements. Generally the conventional switches forwards the packets which are called the Forwarding Plane and do…
Setting different kernel version in Ubuntu 16.04.4 as default.
In Ubuntu we can set different installed kernel version as default so that during next boot time Ubuntu can boot from that default kernel version as per requirement. There can be many reason for setting different installed kernel version as default example: Ubuntu is unable to boot with current installed or upgraded kernel version. After…
Ubuntu throwing /boot full error on screen.
I Love Ubuntu after Fedora it is my preferred OS who live in my personal Laptop. Today I was trying to install Oracle Virtualbox in my Laptop during building initrd image I start getting boot partition full error on screen. Also in apt-get installation screen I got below error message due to no space…