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Questions tagged [kvm-virtualization]

KVM (for Kernel-based Virtual Machine) is a full virtualization solution for Linux on x86 hardware containing virtualization extensions (Intel VT or AMD-V). It consists of a loadable kernel module, kvm.ko, that provides the core virtualization infrastructure and a processor specific module, kvm-intel.ko or kvm-amd.ko. KVM also requires a modified QEMU although work is underway to get the required changes upstream.

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Getting windows virtio mounted/installed for KVM

There might be an easy answer to this. I have exhausted my search on google for a solution. Here's my problem. I need to get Windows working on a KVM vps with virtualizor CP. As I get into windows ...
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4answers
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Forwarding ports to guests in libvirt / KVM

How can I forward ports on a server running libvirt/KVM to specified ports on VM's, when using NAT? For example, the host has a public IP of 1.2.3.4. I want to forward port 80 to 10.0.0.1 and port 22 ...
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3answers
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Install windows 2012 R2 over KVM-virtualizaton

I'm trying to install Windows Server 2012 R2 over linux KVM-virtualization. The installation process stops and requires drivers to continue. I'm trying with virtio drivers from fedora but doesn't ...
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6answers
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KVM Guest installed from console. But how to get to the guest's console?

I'm trying to install a fully virtualized guest (Fedora 14 x86_64) on KVM (RHEL 6), using command-line only (both hypervisor and guest). It goes without errors, and without a tangible result . I'd ...
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1answer
3k views

How can I run Startup Repair on a KVM virtualized Windows Server?

I have Windows Server 2008 R2 running virtualized in a KVM virtual machine. Recently the virtual machine decided to stop booting, and it offered to Launch Startup Repair. However, upon entering ...
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3answers
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Snapshot/rollback for libvirt+KVM?

I've recently begun using KVM for my development/test environment on a Linux host system with 8G memory. Prior, I was using VMware Fusion for my virtual environment, but my Macbook only has 2G memory. ...
12
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1answer
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KVM guest io is much slower than host io: is that normal?

I have a Qemu-KVM host system setup on CentOS 6.3. Four 1TB SATA HDDs working in Software RAID10. Guest CentOS 6.3 is installed on separate LVM. People say that they see guest performance almost equal ...
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5answers
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Port Forwarding from Host to Guest with libvirt 0.8.3 Using KVM on Ubuntu

The host has a single external IP available, so I set my KVM guests up with NAT. How do I set up a port forwarding to forward some of the requests from the outside to the guests? I couldn't find ...
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1answer
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windows server 2012 resolution woes with vga

I have two windows vms, windows server 2012 and windows server 2008. Both use kvm and libvirt. I recently decided I wanted to increase my screen resolution options, which required changing from the ...
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4answers
7k views

Improving IO with FlashCache

I have a server with 2 HDD's (2x 1 TB), running in RAID 1 (SW-RAID). I want to improve IO performance by using flashcache. There are running KVM virtual machines on it, using LVM. Regarding this, I ...
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2answers
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mount qcow2 snapshots

I'm running some Xen-servers and started migrating to KVM. Currently my guests are either running on raw-images or LVMs. I found libvirt providing some very nice snapshot features (virsh snapshot-...
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4answers
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Virtualized CPU cores vs. threads

We've got a KVM host system on Ubuntu 9.10 with a newer Quad-core Xeon CPU with hyperthreading. As detailed on Intel's product page, the processor has 4 cores but 8 threads. /proc/cpuinfo and htop ...
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5answers
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How to automatically start VM created by virt-manager?

I have created a virtual machine with virt-manager that runs on kvm/qemu. The machine works well when started through virt-manager. However, I would like to be able to start and stop the VM through ...
4
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4answers
388 views

How to create a environment where each user's vm is isolated

I want to know if it is possible to create a multi user environment using KVM libvirt that is each user can create there own vm but that must not be accessible by others saw this Multiuser use of virt-...
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5answers
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Convert directory to QEMU/KVM virtual disk image

I have a directory filled with data at /var/backups/disk1 that I want to convert into a virtual disk image which I'll then be able to boot using QEMU or KVM (the directory contains the file system for ...
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3answers
10k views

attaching usb dongle to KVM VM

I'm struggling to connect a usb device, that gets detected correctly by the host, to a kvm vm. I have a freshly installed Ubuntu Server 14.10 as KVM/QEMU host. I set up an Ubuntu vm using this ...
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2answers
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How do I configure bridged networking for VMs

I'm setting up a KVM virtualization server in CentOS 6. How do I configure bridged networking? (I think I need network interface eth0 to be accessible to VMs) I have tried to follow this guide: How ...
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8answers
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Virtualization: Guest in guest?

Does it make any sense to run a virtual machine with a "master" guest, and in that master guest run many other guests? Has anyone tested this? Is it even possible? Are there better ways to accomplish ...
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1answer
2k views

KVM: Run a script when a guest is shutdown from within?

I am running KVM as virtualization engine. Is there a way to make QEMU/libvirt run a script on the host when a guest is shutdown from within (shutdown -h now)? I want to be able to run some custom ...
3
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3answers
4k views

Installing Pfsense in KVM

I am trying to install PFsense in KVM and it keeps failing for not finding an installable distribution. What does the following error mean? Fetching volume XML failed: Storage volume not found: no ...
2
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1answer
1k views

Persistent Network Configuration using KVM and libvirt

Our environment will have a KVM host setup dynamically using kickstart (easy enough). The hard part is dealing with network configuration and keeping VLAN configuration (and possibly bridge/host ...
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3answers
3k views

KVM guest is unable to access the internet

I have a Debian host that has several allocated IPs and KVM with a Debian guest using a bridged network. The guest is completely unable to reach the network, including the LAN or even the host. ...
118
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3answers
109k views

Difference between KVM and QEMU

I have been reading about KVM and Qemu for sometime. As of now I have a clear understanding of what they do. KVM supports hardware virtualization to provide near native performance to the Guest ...
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12answers
190k views

How do you increase a KVM guest's disk space?

I setup an Ubuntu guest on a CentOS KVM host with initially 6GB of disk space. How do I go about increasing the Ubuntu guest's disk space from the command line? EDIT #1: I'm using a disk image file (...
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7answers
62k views

Xen vs. KVM in performance

What is faster on the same hardware, Xen or KVM? I'm trying to pick-up a virtualization technology to work, which gives the best performance. There are some benchmarks here that I found on the ...
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2answers
81k views

Difference between Xen PV, Xen KVM and HVM?

I know that Xen is usually better than OpenVZ as the provider cannot oversell in Xen. However, what is the difference between Xen PV, Xen KVM and HVM (I was going through this provider's specs? Which ...
21
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4answers
26k views

KVM/qemu - use LVM volumes directly without image file?

I'm not quite sure how to phrase this question (hence the poor title), so let me provide an example of what I'm trying to do. On my (old) Xen host, I'm able to present LVM filesystems directly to ...
21
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5answers
78k views

KVM: Which CPU features make VMs run better?

We are using Ubuntu 12.04 with the following parameters: Dell R910 Kernel 3.2.0-25-generic #40-Ubuntu SMP x86_64 x86_64 x86_64 GNU/Linux kvm 1:84+dfsg-0ubuntu16+1.0+noroms+0ubuntu13 qemu-kvm 1.0+...
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2answers
7k views

KVM on Illumos (OpenIndiana vs. SmartOS)

I'm considering virtualizing a number of guests onto a single server running a recent port of KVM to Illumos. It sounds like my two primary options will be OpenIndiana and SmartOS. The distribution ...
15
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2answers
39k views

Strongswan vpn tunnel connected but the traffic is not routed through it

I have just set up a vpn tunnel site-to-site with strongswan (4.5). The tunnel looks fine and connected to the other side, but seems there is a problem routing traffic through the tunnel. Any idea? ...
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9answers
30k views

How do you synchronise huge sparse files (VM disk images) between machines?

Is there a command, such as rsync, which can synchronise huge, sparse, files from one linux server to another? It is very important that the destination file remains sparse. It may be longer (but ...
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3answers
8k views

LVM volume group shared between KVM/libvirt host and guests: is this a bad idea?

I have just built a shiny new KVM/libvirt-based virtual machine host, containing 4 SATA II hard drives, and running CentOS 5.5 x86_64. I have decided to create virtual machine disks as logical ...
15
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1answer
54k views

how to delete a guest after creating it with virt-install

I created a KVM guest from the command line with virt-install where I used the command line options --disk pool=vg0,size=20 and --name virt1.example.com. How can I delete this KVM guest from the ...
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3answers
7k views

No IPv4 address assigned to KVM VM

I'm having trouble setting up KVM w. bridged networking in Ubuntu 10.10. I'm starting my VM through virsh, after this I can see the kvm process and vnet device on the host machine, but the new ...
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2answers
7k views

Backup of KVM guests when using qcow2 disk files

I got a Ubuntu (hardy) system used for virtualization using KVM. Each guest got it's own qcow2 file used as disk. Guests are running Ubuntu (hardy). What would a good backup strategy be for such a ...
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2answers
4k views

understanding relationship between Qemu and KVM

What is the difference between KVM and Qemu? As I understand, latter is able to provide "user mode emulation" which means that one can run a single executable built for some other architecture like ...
12
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5answers
19k views

Is online disk resize possible with KVM?

We're evaluting KVM for Linux virtualization on a few projects. All is going well so far. But one of our requirements is the ability to add disk space to a running guest without rebooting or taking it ...
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5answers
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Solidworks: activation license mode is not supported in this virtual environment (Qemu-KVM)

The question is not around Solidworks actually, so please continue to read. The whole idea of virtualization is to be hardware independent. Before our eyes a whole new dependency level is being ...
11
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8answers
18k views

Get list of DHCP clients with KVM+libvirt?

I have several VMs running on Ubuntu 9.10 via KVM+libvirt. I want to be able to find out the IP address that has been assigned to each host without physically opening a physical "console" to each ...
9
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1answer
2k views

KVM/Qemu, Ubuntu: Why do more guests CPUs enhance Disk-I/O rapidly?

We have an Heartbeat/DRBD/Pacemaker/KVM/Qemu/libvirt cluster consisting of two nodes. Each node runs Ubuntu 12.04 64 Bit with the following packages/versions: Kernel 3.2.0-32-generic #51-Ubuntu SMP ...
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3answers
28k views

KVM and virtual to physical CPU mapping

I'm a relative late comer to the virtualistion party, so you'll have to forgive me if this seems like an obvious question. If I have a server with 12 cores available, does each KVM guest have access ...
3
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2answers
8k views

KVM/Libvirt bridged/routed networking not working on newer guest kernels

I have a dedicated server running Debian 6, with Libvirt (0.9.11.3) and Qemu-KVM (qemu-kvm-1.0+dfsg-11, Debian). I am having a problem getting bridged/routed networking to work in KVM guests with ...
9
votes
1answer
23k views

Mapping USB drive direct to libvirt KVM virtual machine?

I am searching for information on mapping an existing drive (USB drive) to a KVM virtual machine using libvirt. I have been going over http://libvirt.org/formatstorage.html#StoragePoolTarget. But I ...
7
votes
2answers
13k views

Am I using virtio for my KVM guest?

In one of my KVM guest, when I typed the following command, I get the following /sbin/lsmod | grep vi virtio_balloon 3692 0 So does it mean I am using virtio? Update: When I type cat "...
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4answers
6k views

libvirt and qemu/kvm -snapshot option

Using libvirt, I want to use QEMU's '-snapshot' option. That way, when the machine shuts down, all of the disk changes that were made get destroyed. Here is the manual for the -snapshot option: ...
5
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1answer
5k views

Why does host swap out VMs when there are 16GB of buffer cache and swappiness = 0? [duplicate]

I have a desktop running Ubuntu Quantal using OpenStack Folsom on an Intel i5 with 32 GB RAM and 2 GB swap. I'm running 7 VMs each sized like a EC2 m1.small, so 1.7 GB RAM each. I'm using KVM. As I ...
4
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3answers
3k views

Is KVM stable enough for production use in 2011?

We are planning to virtualize the existing infrastructure by an open source virtualization solution. KVM and Xen are on the final list. Big cloud players are still using Xen, and we found that KVM is ...
4
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2answers
1k views

Network freezes with KVM/libvirt and ip_forward = 1

I'm using KVM and libvirt and experience small network freezes on the host and the guests every 2-3 minutes or so. The freezes last 1-2 seconds. The used OS is Ubuntu 10 LTS server edition. I'm ...
4
votes
2answers
16k views

pfSense Site-toSite VPN with OpenVPN connects but won't route traffic

Using two pfSense routers, I've created a shared-key VPN between 2 sites. Both routers are pfSense 1.2.2. The pfSense box at the client site is the gateway router for that site, but at the server ...
4
votes
3answers
10k views

KVM booting off-image kernel and existing partition

I am in the process of switching from Xen to qemu-kvm. My current Xen installation has a number of LVM volumes each with a partition (rather than a full disk image). In Xen, I start each VM with a ...