A virtual machine (VM) is a guest Operating System running in a completely isolated environment within a normal host operating system. Modern virtual machines are implemented with either software emulation or hardware virtualization or (in most cases) both together.

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148
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16answers
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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 ...
48
votes
3answers
37k 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 ...
42
votes
10answers
14k 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, ...
36
votes
10answers
70k views

How to automatically start and shut down VirtualBox machines?

I need to run a software system that is intended to be installed as an appliance on a dedicated machine. In order to save energy, I plan to run the system on a VirtualBox VM instead. The host is a ...
36
votes
2answers
33k views

How do I run 32-bit programs on a 64-bit Debian/Ubuntu?

I have a 64-bit (amd64 a.k.a. x86_64) Debian or Ubuntu installation. I need to run 32-bit (i386/i686) programs occasionally, or to compile programs for a 32-bit system. How can I do this with a ...
24
votes
6answers
52k views

File permission issues with shared folders under Virtual Box (Ubuntu Guest, Windows Host)

I am using Ubuntu on Virtual Box and I have a folder which is shared between the host (Windows) and the VM (Ubuntu). When I open any file in the share folder in Ubuntu, I can not change it as its ...
15
votes
1answer
3k views

how to send CTRL-ALT-Fn to virtual box guest Linux?

This should be a simple question: Host OS: Arch Linux Guest OS: Arch Linux (GNOME) How can I send Ctrl+Alt+F1 to my Guest Linux OS?
14
votes
1answer
11k 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.
14
votes
3answers
28k views

VirtualBox: two network interfaces (NAT and host-only ones) in a Debian guest on Ubuntu

I created a Debian VM on VirtualBox with two interfaces: a NAT one (for accessing internet) and a host-only one. However, I do not know how to make both interfaces work at the same time. If I the ...
14
votes
7answers
15k 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. ...
12
votes
4answers
4k 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 ...
11
votes
4answers
4k views

Good distro for a VM?

I want a lightweight Linux VM that I can run with VirtualBox on Windows so I can test how to deploy PHP apps, Mono apps, etc. I don't need the UI and was thinking of going with the Ubuntu server ISO. ...
11
votes
4answers
6k views

Convert image of a partition into image of a disk with partition table

I have an image of an existing partition generated with dd if=/dev/sdXN of=image.bin. Now I want to use this image as the basis for a virtual machine. I know how to convert the image into a format ...
11
votes
3answers
675 views

What are benefits and downsides of unprivileged containers?

The technical explanation of what is unprivileged container is quite good. However, it is not for ordinary PC user. Is there a simple answer when and why people should use unpriviliged containers, and ...
11
votes
1answer
5k views

Using a LVM partition as a Virtualbox drive

Is it possible to use a LVM partition as a Virtualbox disk? I can't find any option to use a device as a Virtualbox disk, only disk images.
10
votes
3answers
2k views

What's causing VirtualBox OSE to hang my machine?

I'm using VirtualBox OSE and recently, when I run Ubuntu 10.10 on it, my machine tends to hang, forcing me to hard-reset it (not good). How do I start finding where the problem is? Here's the last ...
9
votes
3answers
454 views

Physically break into box? (Memory & disk)

I have a VPS. I might be able to encrypt my partition but I havent tried. My VPS company I believe can reset my root password although the only SSH key I see is my own. With all my data I have it ...
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 ...
9
votes
2answers
3k views

How can I install a 64bit Linux virtual machine on a 32bit Linux?

I've got a computer (Intel core i5) with 32bit Linux installed (ubuntu 11.04) and I would like to install a 64bit Linux virtual machine on it so I can test 64bit command-line applications on it.
9
votes
1answer
13k 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 ...
8
votes
4answers
11k views

Booting the already installed Windows from the VirtualBox installed in Ubuntu

I want to boot the Windows which is installed in laptop's internal harddisk(/dev/sda1) from the VirtualBox installed in my Ubuntu. Can somebody tell me how to do this in VirtualBox.
8
votes
2answers
4k 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 ...
8
votes
1answer
726 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
9answers
8k views

Find out if the OS is running in a virtual environment

Is there any way to find out if the OS I'm running (actually installing) is running in a VMWare machine. I need to disable ntp settings if the automated install is done on a virtual machine but keep ...
7
votes
3answers
10k views

Which *nix distro is most lightweight for running virtual machines? [closed]

EDIT: This question was expanded to include other Unix-like distros such as Hurd and BSD. Before anyone wonders, I did read related questions and answers; I think I have a sufficiently unique ...
7
votes
3answers
13k views

Oh no! Something went wrong! Installing kali linux

I am trying to install a virtual machine running Kali (Formerly backtrack) 1.0.7 in 64 bit. My host machine is a 64 bit MacBook pro running 10.7.5. I am using Oracle VirtualBox version 4.3.12. The ...
7
votes
1answer
4k views

Linux - LXC; deploying images with tiniest possible X11

is it currently possible to setup LXC containers with X11 capabilities? I'm looking forward for the lightest available X11 container (memory-wise), hardware acceleration a plus but not essential. If ...
7
votes
3answers
28k views

CentOS on HyperV - eth0 not in ifconfig?

I've launched a CentOS install in HyperV and assigned a NIC the same way I've done on an Ubuntu VM, however, the device simply isn't picked up. Only my loopback is found by ifconfig. How should I go ...
7
votes
1answer
218 views

KVM reports strange CPU usage peaks (bash infinite recursion)

On a KVM machine running Fedora 20 I ran ulimit -s unlimited (this removes limit on stack size) and an experimental torturing testing script. All this script does is just infinite recursion: ...
6
votes
6answers
5k views

Install virtual machine as non-root?

Is it possible to install any virtual machine software as non-root user and run it ? Which VM's are possible to be installed with out need of root access ? If it is not possible what would be the ...
6
votes
3answers
210 views

Is it 'possible' to transfer a VM to the metal?

How can one take a VM and make it run on the machine?
6
votes
1answer
5k views

ssh-agent forwarding for a Vagrant VM

I'm currently looking at setting up a Vagrant environment on my Mac machine, so that I can run vagrant up and it will then install rbenv and ruby and all I need. Then I have a Bash script that will ...
6
votes
2answers
778 views

Xen/KVM/LXC for testing packages

On Debian Stable, I would like to be able to create a new instance of the OS, use apt-get to install some Unstable packages with dependencies, then cleanly delete the whole thing when I'm done. ...
6
votes
2answers
805 views

Good tutorial for setting up a KVM/Xen box and advice on which would be better

I've got a dual xeon, 2GB, 75GB hd server that I'd like to turn into my dedicated virtual environment. Currently I'm using VirtualBox locally to run a mock cluster for Cassandra and Nginx/Haproxy, ...
6
votes
1answer
3k views

LXC container network/routing issues

I have been experimenting with LXC virtualisation in order to run virtual machines on a dedicated server, but am having trouble setting up the networking properly. I am using veth bridged networking, ...
6
votes
1answer
2k views

Creating VLANs between network namespaces

I want to implement the topology shown in the figure below using network namespaces (ns1 to ns4). ...
6
votes
1answer
542 views

Convert Debian Live USB persistent filesystem to a standalone installation

How would I convert a persistent filesystem (live-rw) from a Debian Live USB to a standalone, bootable installation that can be run on a VM? What I've tried Chrooting and installing a bootloader ...
6
votes
1answer
3k views

Xen on openSUSE 11.4

I have done a few installs of openSUSE to use as a Xen dom0 and have not got it working yet. These are the steps I followed: Installed openSUSE 11.4 from Live KDE CD. Installed all updates via ...
5
votes
3answers
14k 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
5answers
17k views

How to improve Windows perfomance when running inside KVM

I use Ubuntu 12.04 64-bit and KVM, my CPU is Core i5 3.3 GHz and I have 8 GB of DDR3 RAM. I run Windows 7 in KVM and it's extremely slow. My co-worker use Debian on the same PC configuration and can ...
5
votes
2answers
681 views

Do I need acpid in a virtual machine?

I'm always wondering if power management facilities in a virtual machine is necessary? i.e acpid. And I'm not sure if they still function in a virtual machine.
5
votes
3answers
715 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 ...
5
votes
3answers
726 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
5k views

What are some alternatives to virtualbox

I have a lot of trouble lately installing on a box that i can't reboot or change the kernel. Is there any other package that supports gre tunnels (if the os supports ) that i can run on linux? ...
5
votes
3answers
2k views

What are the differences between various VM software?

I have only ever used VirtualBox and I would like to know, for example, what could I be missing from other offerings. I have heard of KVM and VMWare and I'm sure there's others. Short of reading ...
5
votes
1answer
9k views

Can't resize a partition using resize2fs

I recently resized the hard drive of a VM from 150 GB to 500 GB in VMWare ESXi. After doing this, I used Gparted to effectively resize the partition of this image. Now all I have to do is to resize ...
5
votes
1answer
995 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 ...
5
votes
2answers
392 views

Choosing virtual machine software on Linux

There are many virtual machine software out there. Even some are included into mainline Linux. What differentiates them, and what criteria should one ponder while choosing one?
5
votes
1answer
603 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 | ...