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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42
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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 ...
54
votes
11answers
36k 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, ...
6
votes
2answers
3k views

Reading a filesystem from a whole disk image

I ran these commands: VBoxManage clonehd d6b9f0a5-98df-48ca-83c8-91a0809ec349 --format RAW Debian.raw sudo dd if=~/.VirtualBox/HardDisks/Debian.raw of=/dev/sda5 When I try to mount the partition, I ...
57
votes
3answers
47k 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 ...
166
votes
16answers
76k 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
10answers
86k 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 ...
7
votes
3answers
13k 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 ...
8
votes
1answer
810 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 ...
5
votes
2answers
5k 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 ...
7
votes
2answers
2k 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 ...
5
votes
5answers
3k views

Share memory between a virtual machine and the host

Through shmget and shmat, I am able to access the data stored in one program from another program. Here's the gist of the code: key=ftok("shared.c",'c'); shmid=shmget(key,1024,0644|IPC_CREAT); ...
4
votes
2answers
79 views

Syntax error unexpected end of file [closed]

I have written a shell script which allows me to create a user and assign them to a group but I keep getting the error line 19: syntax error: unexpected end to file What am I doing wrong? Would it ...
2
votes
1answer
2k views

virt-install complains “error: no such option: --network-bridge:br0”

I was following the directions here to set up a VM in CentOS 6.4 i386/686. But I'm getting this error: $ sudo virt-install --network-bridge:br0 --name vm1 --ram=1024 --vcpus=1 --disk ...
2
votes
1answer
2k views

How to achieve the effect of chroot in userspace in Linux (without being root)?

The goal is to install and run programs in a displaced (relocated) distro (whose / must not coincide with the global /) inside a host Linux system. The programs are not adapted for using a different / ...
0
votes
1answer
796 views

Accessing file from the Windows host in a VirtualBox virtual machine

I am running Ubuntu 14.04 as the guest operating system in a VirtualBox virtual machine. The host runs Windows 8 (24GB). I want to access a folder of the host inside the guest. Since the source is ...
38
votes
6answers
83k 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 ...
33
votes
1answer
21k 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.
28
votes
7answers
23k 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
1answer
6k 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 ...
11
votes
4answers
14k 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.
13
votes
4answers
5k 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 ...
17
votes
11answers
18k 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 ...
15
votes
4answers
8k 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
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 ...
11
votes
1answer
6k 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.
4
votes
1answer
7k views

CentOS doesn't know what the internet is

So I've done my share of investigating this problem... I just recently created a CentOS 6 VM on my LinuxMint box using VirtualBox. I left all the recommended values the same upon creation (8GB HDD, ...
8
votes
1answer
2k views

GParted LiveCD fails to start

I have a VM setup in VirtualBox (LinuxMint 17.1). But I'm trying to boot to GParted so I can resize a partition. I'm using gparted-live-0.22.0-2-amd64.iso and it boots correctly. I've tried every ...
8
votes
1answer
2k 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 ...
18
votes
1answer
4k 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?
7
votes
2answers
2k views

Can virtfs/9p be used as root file system?

Is it possible to use a folder shared from the host to the guest via virtfs/9p as the root file system inside the guest? Loosely related to my previous question: Can virtfs/9p be used to share the ...
6
votes
3answers
214 views

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

How can one take a VM and make it run on the machine?
3
votes
1answer
2k views

Virtualbox under Proxmox

On a Jenkins Master-Slave configuration and need to run on the slaves Kitchen tests on several jobs. Kitchen for those who do not know it, runs infrastructure on demand using Vagrant and VirtualBox ...
2
votes
0answers
164 views

How do I ssh into a new virtual machine?

note by derobert: problem was resolved in chat, starting around http://chat.stackexchange.com/transcript/message/24666451#24666451 if someone wants to write up an answer. Turns out the bridge wasn't ...
6
votes
1answer
5k 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. ...
6
votes
1answer
22k 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 ...
6
votes
1answer
2k views

Can VirtualBox return IP address for launched VM?

I would like to start my VM from the command line and without the GUI using the following command: VBoxManage startvm <MY_VM> --type headless and the SSH into it from the next prompt. The ...
4
votes
2answers
3k 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
3answers
437 views

how do I build a bridge between two virtual machines?

I have used virt-install to create two CentOS 7 virtual machine guests on a CentOS 7 host computer. One virtual machine is called webvm, and hosts web sites on a private network. The other virtual ...
3
votes
4answers
650 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 ...
2
votes
1answer
759 views

Can QEMU/KVM+OCFS2 be configured to punch holes in sparse image files when files are deleted in the guest?

I'm using sparse raw image files for guest VMs and OCFS2 on the host (local-only, not clustered) for the reflink feature. I understand from Googling around that OCFS2 is one of the filesystems that ...
1
vote
1answer
582 views

How to use Vagrant provisioning to install a package without download?

The title says it all. I'm using Vagrant boxes for several purposes, and in most cases the prepared boxes I can download are totally sufficient. However, sometimes I need one or a few additional ...
1
vote
1answer
754 views

What precautions should I take running Windows 7 on a VM on Linux?

I'm thinking of running Windows 7 on a virtual machine on VirtualBox on top of Linux, so that Windows is sort of a "self-contained sandbox" (especially in terms of data storage) for things that ...
1
vote
1answer
2k views

Guide to installing Xen on CentOS 5.9 (That is still valid)

I need an idiots guide to installing Xen Hypervisor on CentOS 5.9 We attempted to install it on 6.3 before, but completely failed, so we reverted to 5.9 to see if we had more luck. We had issues ...
10
votes
2answers
4k 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
3answers
27k 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
3answers
901 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
6answers
331 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 ...
3
votes
1answer
2k views

Measuring CPU %steal on VMware and Hyper-V hypervisors

For Xen Linux guests, %steal time is readily available via top and other utilities. Is it possible to get this and related metrics from within a Linux guest when running a non-Xen hypervisor such as ...
2
votes
1answer
147 views

how do I create an appropriate drive for a libvirt virtual machine?

I am trying to use virt-install to create a CentOS 7 virtual machine in a CentOS 7 host. Towards that end, I have been reading the virt-install documentation at the RHEL web site, and I have also ...
2
votes
2answers
33k views

Wireless connection not figuring in VMware Workstation 10(Kali-Linux)

I just installed kali-linux on my VMware workstation 10. I had to check for the wireless connection in the kali-linux. I tried to check for the wireless-network connection(WiFi);but,it was incorrectly ...