Virtualization is the process of using software to create a virtual resource of something; usually, it refers to hardware virtualization, the act of running an operating system (referred to as guest) inside an host system.

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132
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16answers
39k views

Any reason NOT to run Linux in a VM all the time?

I've switched to using Arch Linux for most of my day to day work and don't need Windows for anything but gaming and the couple of apps that aren't ported to Linux like OneNote. My Linux distro is ...
42
votes
3answers
31k views

Does LVM impact performance?

I have to migrate a few servers to Linux, and one important aspect that I need to evaluate is that my new host system must have elastic storage capacity. Naturally, doing some basic research, I came ...
34
votes
8answers
6k views

Easy way to determine virtualization technology

I have command line access to a Linux machine which may or may not be virtualized. I want to determine what kind of virtualization technology it runs on, if any (VMWare, VirtualBox, KVM, OpenVZ, Xen, ...
11
votes
7answers
10k views

Should LVM partitions be used in virtual machine images?

Should LVM be used for the partitions when creating VM images (e.g., KVM images)? It seems like it adds complexity if you want to, say, mount a qcow2 image in the host if the image has LVM partitions. ...
10
votes
4answers
3k views

Lightweight isolated linux environment

I want an isolated (guest) Linux environment on my computer that I can mess up without worrying about the host. E.g. install a lot of stuff from source without package management, pollute environment ...
9
votes
2answers
2k views

Tools for Monitoring Steal Time (st)

We're running on a virtual "dedicated" server, which should, in theory, mean that we're the only guys on the server. In practice.... I'm thinking we might not be. Notice that although it looks ...
8
votes
1answer
667 views

Lightweight virtualization on Linux with user isolation

What Linux-on-Linux virtualization technologies provide user isolation? Specifically, I want root in the virtual machine not to have any privilege on the host. This was not the case for LXC, but was ...
7
votes
1answer
5k views

Linux LXC vs FreeBSD jail

Are there any notable differences between LXC (Linux containers) and FreeBSD's jails in terms of security, stability & performance? On first look, both approaches look very similar.
7
votes
1answer
11k views

Do VirtualBox or VMWare use the Intel VT-d feature?

I'm thinking about a new laptop, which has Intel VT support, but recently I discovered a feature other than Intel® Virtualization Technology (VT-x), which is Intel® Virtualization Technology for ...
6
votes
2answers
3k views

Fast X for LXC guest on localhost?

How can I run X apps inside an LXC container efficiently? ssh -Y guest is too slow - there is no graphics acceleration with ssh -Y - everything has to travel over the virtual network with the ...
6
votes
1answer
1k views

Creating VLANs between network namespaces

I want to implement the topology shown in the figure below using network namespaces (ns1 to ns4). ...
5
votes
3answers
7k views

“echo 3 > /proc/sys/vm/drop_caches” - Permission denied as root

I am currently having some issues with the cache. It is a little too much right now so I wanted to clear it. I googled and found this little command: sync && echo 3 > ...
5
votes
8answers
2k views

WebGUI for Virtualization?

Are there any virtualizations that can be accessed via a WebGUI too? I mean the administration part is enough on a terminal, but we need a virtualization/webgui solution for "customers". So that ...
5
votes
3answers
584 views

Can libvirt check if virtual machine is fully booted? Can another tool?

I currently have small VM to do certain tests (it has multiple benefits - like testing on another distribution, Fedora 15, as well as running make distcheck without the problem of polluting /). ...
5
votes
1answer
1k views

Does quiesce exist for Linux?

Quiescing a file system allows you to make a backup of the database while it is still running and other programs and their data as well. The application generally needs to be notified of the quiesce ...
5
votes
6answers
305 views

How can I be sure that my server is not virtualised?

How can I make sure that my Linux server is running on a non-virtualised real box? This is the scenario I am thinking of: I install some distro on a rack-mounted server, I rent some rack space on ...
5
votes
2answers
94 views

How to set up interchangeable VM guest/hosts

I'm looking for a way to set up a computer so that the disk is partitioned for multi-booting to two operating systems: Linux and Windows. Whichever one is booted, I want the other to be accessible as ...
5
votes
1answer
206 views

Running one OS per core

I'm interested in using a COTS board like the Wandboard for a project. On one hand I'd like to use something like Ubuntu for user interaction, sounds, TCP/IP stuff, etc. But I also need an RTOS like ...
4
votes
2answers
1k views

Openstack for home cloud hosting

I am experimenting with a couple of technologies that I soon may have to use at work. So for now, I was thinking about duplicating the environment which I may have to create for my office at home so ...
4
votes
2answers
8k views

How to find VM OS installation media file in the Proxmox Web Interface?

I have installed Proxmox and wanted to create a VM by using the Proxmox web interface GUI (now the version is 2.0-38/af81df02) However I have problem to find my Guest VM OS installation CD/DVD ISO ...
4
votes
1answer
525 views

Emulate unplugging a network cable with qemu-kvm

[Background: I'd like to actually test How to take down a static network interface when not connected? ] I'm setting up a QEMU-KVM virtual machine using libvirt (via virt-manager). I put two NICs on ...
4
votes
1answer
243 views

setup kvm on a wireless interface on a laptop machine

I am trying to setup KVM in ubuntu 14.04 host machine. I use a wireless interface to access the internet in my machine. I have setup the wireless interface in my /etc/networks/interfaces as below. ...
4
votes
2answers
3k views

CPU usage of KVM

I have a linux host with 4 KVM linux guests. All the guest are pretty much idle, having a load of <0.1 inside the guest. Now, if I do a top on the host, each KVM process is using something about ...
4
votes
2answers
821 views

VM benchmark tools?

I would like to benchmark of few XEN-constallations: PV DomU HVM DomU with PV network and disk drivers HVM DomU with emulated IDE and PV network The base will be the same VM with the same ...
4
votes
1answer
516 views

X and xdotool in LXC instead of KVM

So far I am using various xautomation/xdotool scripts in a KVM virtual machine (linux guest) in order to let them do their work and let me work uninterruptedly. I am using a VirtIO disk, but still the ...
4
votes
1answer
1k views

kvm doesn't load Windows 8

I'm launching kvm with the following parameter: kvm -m 2g -smp ncores=2 -hda disk.img -cdrom win8.iso My CPU has VT support and enabled, EDIT I seems to have limited emulate type: pc ...
4
votes
1answer
1k views

One host, two virtual machines that cannot ping each other. How to solve

We have Virtual Machines operating within the KVM environment. We setup one as a dev server running Apache etc., and the other as a Windows development environment. The two environments are setup ...
3
votes
4answers
410 views

How can I zero files out inside a VMware image file so that their space can be reclaimed?

is there a command on Linux to remove a file but zeroing it's contents first? so if i do, something like this: rm -rf /var/cache/pacman/pkg/* it would overwrite each file on that directory with 0 ...
3
votes
2answers
3k views

Are there any virtualization solutions for OpenBSD that aren't from ports?

I'm searching for a virtualization solutions for an OpenBSD host and a CentOS guest. What are my options? I'm searching for one that doesn't use packages from ports. Are there any?
3
votes
2answers
2k views

How to force the time and date settings to refresh from the internet?

I'm running Ubuntu 12.04 LTS under vmWare. When I restart a suspended image, the system clock doesn't detect that the system time is out of date. In the Time and Date settings dialog, I've selected ...
3
votes
2answers
43 views

Running -march optimized software on another architechture?

I'm running an Athlon64 server with LFS and would like to have a local copy of the server in a virtual machine for testing purposes and building software. My PC uses an i7 and the existing server ...
3
votes
3answers
562 views

Problem with mount namespaces under Fedora

I've run into an odd problem regarding mount namespaces on Linux. I have two systems, both X86_64 running kernel 3.2.3-2 under Fedora 16. I am attempting to mount a tmpfs filesystem in a child ...
3
votes
2answers
2k views

Wireless bridged networking in KVM. Why is it so complicated?

I've been using VirtualBox (and sometimes VMWare) for years and I've never had any problem with the virtual network adapters, no matter if the physical ones were wired or not. I also played some time ...
3
votes
2answers
292 views

Terminal-based (non GUI) virtual-computer program?

Are there any terminal-based (ie. non-GUI) virtual-computer programs out there? I've been using programs like VirtualBox and QEMU, but they're obviously GUI-based... I was hoping for a virtual PC ...
3
votes
2answers
311 views

Prevent hacking the grub.conf using a 'live rescue' from a live linux iso

It happened that I had set the grub password in grub.conf. But, using a live linux iso, I was able to delete the password from the grub.conf. Please read the steps for the same mentioned in this link: ...
3
votes
1answer
232 views

How can I remove all my docker images?

Sometimes I just want to clear everything out of docker, and start with a clean slate. Is there a systematic way to just remove all my Docker containers & images? Containers $ docker ps -a | ...
3
votes
2answers
59 views

LiveCD “Remembers” Earlier Partitioning

Whenever I use VirtualBox to install a Linux distro, I usually install the LiveISO onto the hard drive instead of just using it as a live CD. However, sometimes the ISO doesn't install fully (usually ...
3
votes
1answer
23 views

Real-time executive approach, can be run in desktop Linux?

With the real-time executive approach, a small real-time kernel coexists with the Linux kernel. This real-time core uses a simple real-time executive that runs the non-real-time Linux kernel as its ...
3
votes
2answers
509 views

How to add a ms-dos partition table to a loop device?

I recently made a dd from a disk partition. I want to use it as a disk in a virtual machine. I can't because the disk has no partition table. Can I had a partition table to a loop device? how? ...
3
votes
1answer
52 views

memory buffering in virtual machines

Is there any point to doing disk buffer caching in a virtual machine, if the hypervisor OS is doing it? I wonder if buffering in the VM will just waste memory that could be better allocated to VM use, ...
3
votes
2answers
605 views

Does FreeBSD support network virtualization like Crossbow?

Does FreeBSD support network virtualization like Solaris Crossbow? I've tried to follow the VImage links from the FreeBSD wiki page, but the links are mostly dead. If VImage is no longer part of ...
3
votes
1answer
238 views

Custom live distro - ways to detect it is running inside virtual machine (or prevent running in VM altogether)

I am creating a custom live distro that will be a specialist work environment for those of my employees that are on the road. I am looking for ways to detect or, ideally, prevent my live distro from ...
3
votes
1answer
41 views

How to create user cgroups with systemd

I use unprivileged lxc containers in Arch Linux. Here are the basic system infos: [chb@conventiont ~]$ uname -a Linux conventiont 3.17.4-Chb #1 SMP PREEMPT Fri Nov 28 12:39:54 UTC 2014 x86_64 ...
3
votes
2answers
90 views

What is a Linux container and a Linux hypervisor?

I looked at the stackexchange site but couldn't find anything. I looked at the wikipedia entry on Linux container https://en.wikipedia.org/wiki/LXC and as well as hypervisor ...
3
votes
2answers
3k views

Mouting a kvm qemu disk image with multiple partitions

I am trying to mount a KVM-qemu disk image with this command: sudo mount -o loop,offset=32256 centos6.img /mnt/centos6. But it shows this error: you must specify filesystem type. As I have more ...
3
votes
0answers
36 views

Disable buffering in a VM configuration

I am executing some benchmark using a DBMS and virtual machines. And I am using this command free && sync && echo 3 > /proc/sys/vm/drop_caches && free on each Guest, and ...
3
votes
2answers
91 views

How can I force chrooted programs to use a virtual ethernet device?

First off, this is not for security reasons, or for use in a production environment. It's because I want to mess around with different configuration management systems on relatively low-spec ...
3
votes
0answers
114 views

Migrate a qcow2 image between storage pools

I have 2 storage pools. host_images (directory storage pool) remote_images (nfs storage pool) How do I copy qcow images from remote_images to host_images using libvirt APIs? I've tried using the ...
3
votes
0answers
1k views

PCI passthrough with Xen

I am trying to run Windows XP in a Xen DomU virtual machine with a PCIe device, for which there are no Linux drivers, being passed through from a Debian Squeeze Dom0. My hardware supports ...
3
votes
0answers
215 views

Setup Cloudmin on Centos installed in LVM

I installed CentOS 6 with default LVM partition pattern. according to this pattern Can I use Cloudmin and store KVM Disks in LVM as Logical Volume? I think Cloudmin requires creating new logical ...