Introduction We explained how to install VirtualBox on a Centos 7 machine in an earlier article wherein we ran into an issue during the install itself and were unable to start the service. In this article, we will share the diagnostic steps and the consequent resolution after which we were finally able to start the service and use the VirtualBox application. Issue On installing VirtualBox from Oracles’ official repository we received the following message This system is currently not set up to build kernel modules. Please install the Linux kernel "header" files matching the current kernel for adding new hardware support to the system. The distribution packages containing the headers are probably: kernel-devel kernel-devel-3.10.0-123.el7.x86_64 This system is currently not set up to build kernel modules. Please install the Linux kernel "header" files matching the current kernel for adding new hardware support to the system. The distribution packages containing the headers are probably: kernel-devel kernel-devel-3.10.0-123.el7.x86_64 I tried to start the vboxdrv service but the startup failed and given below is the systemctl status output [root@linuxnix ~]# systemctl status vboxdrv.service vboxdrv.service - VirtualBox Linux kernel module Loaded: loaded (/usr/lib/virtualbox/vboxdrv.sh; enabled) Active: failed (Result: exit-code) since Wed 2018-09-19 12:25:08 EDT; 10s ago Process: 58858 ExecStart=/usr/lib/virtualbox/vboxdrv.sh start (code=exited, status=1/FAILURE) Sep 19 12:25:08 linuxnix vboxdrv.sh: vboxdrv.sh: Starting VirtualBox services. Sep 19 12:25:08 linuxnix vboxdrv.sh: vboxdrv.sh: Building VirtualBox kernel modules. Sep 19 12:25:08 linuxnix...Read More
Author: Sahil Suri
Introduction Oracle VM Virtualbox popularly referred to as Virtualbox is a is a powerful x86 and AMD64/Intel64 virtualization product for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL) version 2. When we describe VirtualBox as a “virtualization” product, we refer to “full virtualization”, that is, the particular kind of virtualization that allows an unmodified operating system with all of its installed software to run in a special environment, on top of your existing operating system. This environment, called a “virtual machine”, is created by the virtualization software by intercepting access to certain hardware components and certain features. The physical computer is then usually called the “host”, while the virtual machine is often called a “guest”. Most of the guest code runs unmodified, directly on the host computer, and the guest operating system “thinks” it’s running on real machine. VirtualBox can be installed on host operating systems, including Linux, Windows, Solaris, OS X, and OpenSolaris. From version 2.0 VirtualBox supports 32 and 64bit host and guest operating systems. If you want to install 64bit guests then your processor must support hardware virtualization and the host operating system must be 64bit as well. Hardware...Read More
Introduction In an earlier article, we demonstrated how we could calculate and report the amount of swap memory used by an individual process. In this article, we will explain a kernel parameter related to the use to swap memory. This kernel parameter is called swapiness. Before we talk about swapiness, we’ll briefly explain the concepts of swapping and paging. An overview of memory management in Linux A process normally runs on physical memory where the memory is divided into sets of pages. A page is a 4kb area of memory and is the basic unit of memory with which both kernel and CPU deal. This page size is tunable. Operating systems use virtual memory which is a memory management technique wherein RAM and swap memory are combined gives an application program the impression that it has contiguous working memory. This memory management implementation allows processes requiring a large amount of memory of fork even if the required amount of RAM is not available at that point in time. Swap space: This is storage space allocated on a portion of or the entire hard disk which is used by the operating system to store data pages that are currently not needed. This swap space can be a partition as well as swap file. Although allocating swap space using swap files is not recommended. Swapping and Paging To swap a process...Read More
Take this course
My name is Surendra Kumar Anne. I hail from Vijayawada which is cultural capital of south Indian state of Andhra Pradesh. I am a Linux evangelist who believes in Hard work, A down to earth person, Likes to share knowledge with others, Loves dogs, Likes photography. At present I work at Bank of America as Sr. Analyst Systems and Administration. You can contact me at surendra (@) linuxnix dot com.