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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How to make sysctl network bridge settings persist after a reboot?

I am setting up a notebook for software demo purpose. The machine has 8GB RAM, a Core i7 Intel CPU, a 128GB SSD, and runs Ubuntu 12.04 LTS 64bit. The notebook is used as a KVM host and runs a few KVM ...
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Can't connect to Windows Server 2012 Virtual Machine in Red Hat 6

I have installed a WS2012R2 virtual machine using KVM on Red Hat, It has a bridge connection, Both (Host and Guest) have public IP addresses, both have internet access, both can ping any ip address or ...
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CentOS Qemu+KVM lot of virtual machine processes

I am on host-machine with Centos 6.5, qemu+KVM and 2 virtual hosts in it (behind NAT). Both virtual hosts were configured with Virtual Machine Manager (one of them is with Windows 2003 and other with ...
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Add a second bridge to a virtual machine

We have a ubuntu-12.04 host running another ubuntu-12.04 virtual machine with kvm virtualization and bridged network interface on eth4. This network allows the virtual machine access to the outside ...
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Effect of firewall on virtual machine [on hold]

We have a ubuntu-12.04 host machine that has another ubuntu-12.04 guest machine running in it. The network interface between the two is bridged. I would like to put the host machine behind a firewall, ...
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KVM port-forwarding from ppp0 to VM's bridged NIC not working, but to VM's NAT NIC works?

I've spent a lot of time on this freaky problem, I've created a simple host and VM configuration to try isolate the problem. Terminology in this question Host: The bare metal server VM: The KVM ...
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Linux bridging for KVM

I have a Debian Wheezy machine on which I tried to setup KVM with bridged networking. Unfortunately, the bridge does not appear to forward traffic correctly. My setup is the following: The physical ...
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Setting up a network for a Host Server and it's Guest OS

Is there a standard as to how one sets up networking on a Server Host that will have virtual servers within? In the past I've used virtualmin and set up the nic to have multiple alias such as eth0:1 ...
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dnsmasq(as DHCP server) isn't working in KVM+libvirt envirmont

I'm using dnsmasq as DHCP server in VM environment. But It didn't working. I disabled basic DHCP feature in libvirt. <network> <name>default</name> ...
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How to limit usb 2.0 port to work as usb 1.1 in ubuntu?

Ive got problem with kvm usb forwarding and printing (windows xp guest goes BSOD when i try to print something). Ive been adviced to change usb to 1.1 version. That only kvm works with 1.1 not 2.0 ...
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Adding SSD cache (PCIe) to existing Linux KVM Node with SATA disks

I currently have large KVM nodes utilizing between 8 & 16 RAID10 arrays & hardware raid. We typically provision a single large volume (VM's are backed up off site as well). KVM VM's using LVM ...
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48 views

VPN SSTP windows client can not ping or connect to VPN server but it can talk to every other PC on the local LAN that VPN server is on

So I have an SSTP (with native Windows client) working fine in a sense. My windows client's local IP is 192.168.10.11 , so its local network is: 192.168.10.x The Remote VPN server is behind a router ...
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setting CPU cache size and model for KVM guest

Is there any possibility to create a custom CPU model for KVM Linux guests, or at least to modify parameters such as cache size and model name? I know I can set CPU features, topology and pinning and ...
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Routing private IPv4 addresses internally

I have the following set-up involving two KVM hosts and numerous virtual machine guests on each. The guests communicate to each other on both hosts via [192.168.216.0/24]. [192.168.216.42] is ...
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75 views

Networking in Linux KVM

I want to know if there is any way other than using linux bridges to interconnect interfaces from two virtual machines ? Since I am trying to run private spanning tree implementation in virtual ...
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1k views

KVM: All network traffic to one guest (firewall)

I am currently using a VMWare ESXi 5.5 server for my virtualisation. The network setup is like this: PFSense firewall is the center of it all and connected to: LAN Network (physical NIC 1 assigned by ...
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14 views

libvirt management is slow under ubuntu

I've just done a fresh install of KVM/Qemu under Ubuntu 14.04.2 on an older (C2D gen) server with dual quad core xeons and 24 gb of ram. I'm finding that I'm waiting for operations in virsh for around ...
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windows 7 as kvm guest installation with virtio drivers - detected virtio scsi disk shows wrong capacity

I am trying to install windows 7 64bit as a kvm guest. I read here that I should install the virtio scsi driver during installation. I use virt-install to start my installation from the command line ...
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KVM GPU passthrough working only with cirruslogic vga added, VM goes in paused state if remove cirruslogic and boot with passed-through gpu only

It seems I had this working once but maybe that was when my kernel wasn't trying to load the fglrx kernel module. (I think before it was loading 'radeon' module) Not sure if this was the issue/change ...
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Have GPU Passthrough working both Windows and Linux guests but libGL SDL error linux couldn't find matching glx visual NX x2go freenx

I have GPU Pass-through working with KVM qemu with both Windows 7 and CentOS guest but with Windows I can easily RDP with Remote Desktop mstsc and even run 3D accelerated apps that will make use of ...
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apt-get update can not connect

i run a dedicated ubuntu 10.04 server. i use kvm/libvirt/virsh to run a virtual machine that's also ubuntu 10.04. i bridged the network (1 of 2 IPs is routed via NAT to the LAN, where my VM ...
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CentOS wrong outgoing IP address on forward

I have a rather strange behaviour for me in here. I am trying to forward traffic between two interfaces (one being a bridge) but will not work as intended. Here is the setup: Kvm host has br0 ...
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935 views

How to speed up QEMU on Windows host?

We want to run our Ubuntu 64bit web server virtualized/emulated on a Windows 64bit host. Intended use is to distribute the VM to customers who might not have "elevated" or "admin" rights on the ...
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KVM - Sharing A Physical Hard Drive Between VMs

Installed Ubuntu 14.04 and will be ditching VirtualBox to go to KVM per some recommendations. With that in mind, I have a full physical SATA disk that I would like to share between a few VMs. Is ...
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iptables KVM prerouting SMTP

I have a host machine that has to manage traffic on port 25 and route to port 25 on the KVM machine for postfix deamon like this scheme: WAN --> (25) HOST_MACHINE --> (25) ...
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set tap0 using virt-manager for bridged wireless

After 3 days I finally have kvm guests working on the network via wireless (link below - thanks!): My network is 192.168.1.0/24 on the host: sudo sh -c "echo 1 > /proc/sys/net/ipv4/ip_forward" ...
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884 views

OpenStack Instance not using up full space

I have created new instance with Centos 6.4 with 20 GB Disk Space but when i logging to the VPS and Execute df -h the space shown as the following Filesystem Size Used Avail Use% Mounted ...
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138 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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Very poor disk performance on KVM node - mdadm raid10

For a long period of time, i'm experiencing performance issues on CentOS servers that are used for KVM virtualization. I'm running software RAID-10 with 4 disks (Seagate ST2000DM001, 2TB, 7200rpm ...
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KVM bridged network cannot connect to the server

I installed KVM on my Ubuntu Server 14.04 LTS on OVH dedicated server. I cannot connect to my virtual host over ssh. My server IP: AAA.AAA.AAA.AAA My Failover IP: BBB.BBB.BBB.BBB My config on the ...
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Remote desktop to my KVM virtual machine

I've got a dedicated server running Debian 6. I've set up a windows 7 virtual machine using KVM. Now I'm trying to get Remote desktop working. I'm guessing i have to do some port forwarding. The ...
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482 views

Installing Windows 2012 KVM Guest on Ubuntu 14.10 - unable to VNC into guest

I have a Ubuntu 14.10 (x64) host, and I am using KVM to setup a Windows 2012 R2 guest VM on it. I am using the virt-install command to set things up. I have setup a bridge network in ...
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3answers
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How to efficiently share host's folder with KVM guests?

I am configuring the service which stores plenty of files uploaded by nginx in /srv/storage dir on host system. These files are processed by worker KVM guests which may create new files or assign ...
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Incredibly slow KVM disk performance (qcow2 disk files + virtio)

I'm having some serious disk performance problems while setting up a KVM guest. Using a simple dd test, the partition on the host that the qcow2 images reside on (a mirrored RAID array) writes at ...
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874 views

upstart pre-stop script

I have libvirt/KVM set up on my Ubuntu and before shutting down the machine I would like it to attempt shutting down the VM's using an ACPI poweroff (virsh shutdown), then I want it to stop shutdown ...
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327 views

Ping (DUP) with Linux bridges and tap devices

http://imgur.com/qPoy2QJ I have two Linux (Ubuntu 12.04) VM (running on KVM) that networked together using two Linux bridges as shown above. The network interfaces are Linux TAP devices. The problem ...
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State of VM after 'virsh save'

virsh save vm_name memdump and then virsh restore memdump restores a (running) VM all right. However, a VM is shut off after virsh save. I'm writing a "live" backup and restore script for KVM VMs, so ...
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How can I change Qemu KVM machine architecture from 440fx to q35 with virsh edit or virt-manager

Still trying to get GPU passthrough working and decided to change machine type from older 440fx to q35 ie pc-q35 but if I do virsh edit on the config it refuse to save saying "PCI Bridges not ...
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337 views

qemu-kvm fail to boot Centos 5.3 after Kernel update at the host (feodra)

After updating Fedora 18 to kernel 3.9.x (current 3.9.4), I can no longer boot my Centos 5 guest OS. When I try to boot, the process halt at start and the CPU core work at 100%. If I boot Fedroa ...
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986 views

OpenVPN connects and access to ip works but not url in browser

I have been struggling for 2 days to setup Openvpn access to one of my servers but something doesn't work. First about my setup: My server is Debian 6 installed on vps on kvm environment. I have ...
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1answer
26 views

Mount VM filesystem on host

I'm using Proxmox for virtualization and I need to mount my KVM VM filesystem inside the hypervisor. Is this possible without shutting down my VM? Basically, I need a script that could do following ...
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1answer
1k views

Error while creating VM using virt-manager on Xen

After a great struggle I got my XEN installed now I am using virt-manager and trying to create a VM. Since my H/W doesnt support full Virtualization using the Para Virtualization installation over ...
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1answer
90 views

How to start a new instance of QEMU based on the same image and snapshot?

I have a QEMU image (qcow2) with a snapshot stored in it. Right now I'm using libvirt to start it. However, I want to be able to run more than one instance of the same image snapshot. I guess I can ...
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live-migration failure AND unable to launch an instance

I am having a trouble enablie live-migration in openstack. I follows the steps such as setting vnc_listen = 0.0.0.0 etc. ...
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Linux-on-Linux KVM: Which filesystem should I use for guest and host?

I'm in the process on playing around with KVM and setting up a linux on a linux-server, so I can reboot the (guest)server encrypt the rootFS of the guest without having to do initramfs-tricks to get ...
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What is fastest way to copy a sparse file? What method results in the smallest file?

BACKGROUND: I'm copying a sparse qcow2 VM image that is 200GB in size, but has 16GB of allocated blocks. I've tried various methods to copy this sparse file within the same server and have some ...
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2answers
166 views

Windows Server 2012 R2 doesn't find virtio drivers when installing on KVM

I'm trying to install Windows Server 2012 R2 on a Debian KVM host, but it does not seem to find the drivers. The guest has two drives attached: an install disk and the latest Windows virtio drivers ...
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129 views

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 ...
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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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Assign ipv6 address to KVM guests on bridge mode

System: CentOS 6.5 Network: Bridge on br0 IPv6: ISP Native /64 block. IPv4: ISP address (not internal LAN) Purpose: To assign IPv6 only to guests (manually), I don't want ipv4 address to be ...