How to Fix Metasploit error – requires the bundler gem to be installed? [Solved]
Question: I was stuck with an error “Metasploit requires the bundler gem to be installed” while executing msfconsole from the...
Linux
How to Fix Ruby Installation error: EC_GROUP_new_curve_GF2m undeclared (first use in this function)?
Question: I was compiling Ruby version 1.9.3 on a CentOS machine and landed up with the below error message while...How to find the filesystem of CD/DVD to make it mount automatically : [Linux]
Question: I recently burnt a DVD and was trying to mount it on my Ubuntu box. It worked, when I...Understanding Puppet Resources, Manifests, Modules and Classes with Examples
In this tutorial, I’ll be explaining about Puppet resources, manifests, modules and classes with examples. Also, I assume that you...How to Install and Configure Puppet 4 on CentOS and Ubuntu? [Master and Agent]
Puppet, a popularly known configuration management tool for Unix and Windows based systems that allows an administrator to easily automate...How to use Auditing System in Linux – Configure, Audit Logs and Generate Reports
Before we start discussing about the Auditing system, I would like to ask few questions. How do you monitor the commands...Here’s everything you can do with Nmap – Command Examples
Nmap is an open source network mapper that allows one to scan network of hosts, services, perform security assessment and...How to Fix – Sudo unable to resolve host in Ubuntu?
If you getting an error “Sudo unable to resolve host” while executing sudo command in Ubuntu, then here’s how you can...[OpenStack-Devstack]: Error: Service n-net is not running when executing stack.sh
If you are stuck with an error “Service n-net is not running” while installing OpenStack using Devstack, then here’s how...How to start a VM on a Specified Host/Compute Node in OpenStack Mitaka?
With the appropriate permissions, the user can launch VM on a specified host/compute node in OpenStack Mitaka. All you need to...Why does OpenStack report Hypervisor type as QEMU when libvirt_type is KVM?
I installed OpenStack Mitaka and was curious to check various features in horizon dashboard. For instance, the System > Hypervisors...OpenStack Dashboard Installation Error – error processing package openstack-dashboard-ubuntu-theme [Solved]
While installing OpenStack Mitaka horizon module, I was stuck with an error processing package openstack-dashboard-ubuntu-theme. Below is the snapshot of the...[Openstack]: Set user password when launching cloud images
I recently installed OpenStack Mitaka on my test bed and imported few images from CentOS & Ubuntu repositories. Once the VM...OpenStack Neutron db_sync error – Cannot add a NOT NULL column with default value NULL [Solved]
If you are stuck with an error Cannot add a NOT NULL column with default value NULL while populating or syncing...OpenStack Error – Index column size too large. The maximum column size is 767 bytes [Solved]
If you are getting an error while syncing or populating database of services such as Keystone, Glance, Nova and Neutron, then...Setup command in CentOS 7 throws Error – FirewallD is active, please use firewall-cmd!
I generally use setup or system-config-firewall commands to configure firewall in CentOS machines. But the same commands in CentOS 7...[Ubuntu]: sudoers NOPASSWD option not working
Question: I wanted to install a package as a local user and use sudo wherever required. To do that, I created...[OpenStack]: from keystoneclient.shell import main ImportError: No module named shell
During one node installation of OpenStack Kilo, I tried creating a tenant and the keystone service failed with an error...How to Fix Package installation error – Unable to correct problems, you have held broken packages
Question: I was installing few OpenStack packages on Ubuntu 14.04.4 LTS and landed up with an error Unable to correct...How to create a Linux bootable USB stick on Windows
I need to install Ubuntu on my rack server which didn’t come with the CD-ROM drive, but had USB ports on...