Linux Tech Tips

I'm a Linux System Admin & I play with lots of virtual machines to try & test various software & services. I use Virtual Box for creating virtual machine. Everything works fine except the part of installing same virtual machine again & again which takes a lot of time installing & configuring it. Recently I came across a tool called Vagrant which can automate that process or at least can make it easy for us to make a base image & then create virtual machines from that image without any worry. Now the real work:- Make sure you've Virtual Box installed on your machine, if not already done, download from  https://www.virtualbox.org/wiki/Downloads  & install it. Its available for almost all popular platforms. Download Vagrant from  http://downloads.vagrantup.com/  & install it. Binary packages available for MAC, Windows, debian & RPM based systems. I used Centos 6 heavily so I installed Centos 6. Location specific mirro...

So you need to add an additional hard disk to your VM running the Centos/Redhat/Suse family of operating system, but its in production and you can not reboot it. So how do you go about it? Well, it is rather easy! First, open the "edit settings" window, within the VM, either from the console menu, or by right clicking in the VM through the virtual infrastructure client. Add a hard disk and configure it with the size you require. Finally accept the changes and close the window. After a few seconds, the virtual infrastructure client will shown the reconfiguration being complete. Now logon to the operating system of the VM, as the root user - or use sudo. You will see that the VM does not see the new disk, i.e. running the command: fdisk -l Shows only the existing disks, there is no sign of the new one. What we need to do is, re-scan the SCSI bus, without rebooting the VM. To do this run the following command: echo "- - -...

Last July, Microsoft announced the drivers for Linux source code is available in the Hyper-V virtualization environment. In practice, the 2.6.32 of the Linux kernel version now contains drivers for synthetic Hyper-V, virtual machine including the VMBus, storage, and network components. In detail, it's hv_vmbus, hv_storvsc, hv_blkvsc and hv_netvsc modules. These modules are described in t his article . Out configurations "officially supported", I tested the activation of these modules in new Ubuntu Server 10.04, provided recently with the 2.6.32 kernel. To do this I found this article which explains how to enable these modules, and which I inspire me thus far. Enabling modules Firstly it must ensure that the Hyper-V modules are loaded at startup. To do this, edit the file /etc/initramfs-tools/modules and add the following four lines: hv_vmbus hv_storvsc hv_blkvsc hv_netvsc Then, update the initramfs image: $ sudo update-initramfs...