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, ...

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1answer
2k views

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 ...
9
votes
8answers
2k views

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 ...
3
votes
2answers
8k 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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1answer
1k 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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2answers
2k views

Set startup order for KVM virtual machines via libvirt?

I have some server applications failing because their virtual machine starts up before the database virtual machines. Anyway to configure libvirt to start them up in a certain order and possible ...
15
votes
3answers
21k views

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 ...
17
votes
6answers
35k views

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 ...
12
votes
3answers
13k views

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. ...
15
votes
4answers
9k views

how to rename a VM using libvirt+KVM

How can I rename a VM on KVM+libvirt? I would like it to change the name in the 'inventory' as well as change the name of the storage etc.
7
votes
1answer
13k views

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 ...
14
votes
4answers
6k 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 ...
4
votes
4answers
12k views

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 ...
3
votes
1answer
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Which is better image format, raw or qcow2, to use as a baseimage for other VMs?

I am using a baseimage and based on that creating many VMs. And now I want to know which is better, qcow2 or raw to use for a baseimage. Moreover, can you please tell me if there is any advantage of ...
3
votes
3answers
5k views

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 ...
2
votes
3answers
9k views

Linux KVM on a Virtualbox

Can we install a KVM machine on a virtualbox machine??? Virtual Machine on a Virtual Machine I get the following error when I issue: $ virt-install –-name kvm_client1 –-ram 256 –-disk ...
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vote
2answers
871 views

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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2answers
1k views

Migration from Xen to KVM

I have Xen domU virtual machines running Windows. Each of them are installed in their own LVM logical volumes. I want to migrate them to another server with KVM on lvm to. How can I do this faster ...
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votes
1answer
147 views

Consolidating a server and a desktop on one machine [closed]

What is the best way to have a server and a desktop OS on one machine, with the desktop being displayed on a monitor directly connected? Visualization, with each having a separate guest, seems ideal ...
2
votes
1answer
374 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 ...
0
votes
2answers
796 views

SSH Public Key Authentication only works if active session exists before

I have a rather strange problem with my SSH configuration. I set up my server with the help of a Remote Access Card and configured everything with a KVM viewer. So while being logged into the server ...
32
votes
7answers
60k views

Xen vs KVM in performance

What is faster on 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 subject: ...
29
votes
2answers
18k 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 ...
37
votes
2answers
49k 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 ...
16
votes
4answers
31k 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 ...
8
votes
2answers
5k 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 ...
5
votes
2answers
6k 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 ...
13
votes
4answers
9k 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 ...
8
votes
1answer
1k 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 ...
10
votes
3answers
6k 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 ...
3
votes
3answers
5k 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: ...
15
votes
2answers
2k 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 ...
10
votes
4answers
6k views

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 ...
4
votes
1answer
2k 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
votes
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
votes
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 ...
3
votes
2answers
4k views

Debian: Should I add vlan interface into bridge for KVM?

I am setting up a Debian Squeeze box as a KVM host. I want to add multiple interfaces to each KVM guest so I want them to be on different VLANs. After reading about this, I believe the best method is ...
3
votes
2answers
3k views

KVM on RHEL 6.1 makes host sluggish

I have been running RHEL 5.7 on a host just fine with several VMs (KVM). No major issues. Time came to upgrade to RHEL 6.1 as a few bugs had been fixed in this release. When I start a VM or two under ...
9
votes
3answers
4k views

use LXC under heavier virtualization (Xen, KVM,Hyper-V,VMVare)

Is it possible to use LXC under heavier virtualization (Xen DomU, KVM, Hyper-V, VMVare) ? I would like to use it as security (isolation) tool, the ability to limit resource consumption is not priority ...
3
votes
1answer
3k views

KVM network bridge with public static IP for both host and guests

I have a Ubuntu 10.04 server with 2 public static addresses. There is a KVM guest (also Ubuntu) installed and running. What i want is to give the guest an IP of the host, so that both machines have ...
2
votes
1answer
2k views

libvirt and network filtering with nat - iptables overrides

At first, I want to say: I know, it was done initially wrong and I want to avoid doing everything again from the scratch because of general downtime. I am running libvirt/KVM on RHEL. I've got VM ...
2
votes
3answers
3k 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 ...
2
votes
2answers
2k views

Mount LVM within a disk image

I have a disk image that I made with KVM. The partition layout inside the disk image is as follows. [root@centreon01 2tb-external]# fdisk -lu vdisk1.img Device Boot Start End ...
1
vote
1answer
5k views

Adding Virtio block devices at runtime in Libvirt KVM

I'm running Debian Wheezy Beta 4 with KVM based guest systems which run the same operating system. I'm using LibVirt to manage the virtualisation. What I would like to do is to attach an LVM based ...
1
vote
2answers
15k 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 ...
5
votes
1answer
2k views

Does kern.hz still have any relevance in FreeBSD if “dynamic tick mode” is enabled?

I'm running a FreeBSD 9.0 setup as a virtual machine in a KVM setup. In previous versions of FreeBSD it was common to force the kern.hz setting to a lower value so that the virtual machine does not ...
5
votes
1answer
1k views

KVM virtual machines cannot reach IPv6 web sites

I have a freshly installed Windows Server 2008 R2 SP1 virtual machine which is completely unable to reach any IPv6 web pages, despite apparently having proper IPv6 connectivity. In addition, other ...
3
votes
3answers
5k views

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 ...
3
votes
3answers
1k views

KVM “live migration finished” detection

I'm using KVM (through libvirt actually) for a research project. We're live-migrating a virtual machine between different subnets, so after the migration the IP address and routing tables have to be ...
2
votes
1answer
1k views

Why are eth0 and vmbr0 (bridge) having the same MAC addresses?

I configured my Debian (with KVM on board) as following: /etc/network/interfaces: auto lo iface lo inet loopback auto eth0 iface eth0 inet manual auto vmbr0 iface vmbr0 inet static address ...
2
votes
3answers
3k views

sysctl.conf not running on boot

At what point is sysctl.conf supposed to be read during boot, and why might it not be running? I have the following settings which are not being applied when I reboot: ...