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-...

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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 176....
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2answers
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How to install virtIO drivers for Win 2008 on KVM?

This is a follow up to a pervious question. I have a Ubuntu host with a Win 2008 KVM. To improve performance the network and IO - @dyasny and the documentation recommends installing virtIO drivers. I ...
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6answers
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Will the OS crash if the system partition can't be access for a short period?

An operating system is installed in a virtual machine environment, such as VMWare or KVM. A network shared disk volume (e.g., iSCSI disk) is used as the OS system partition. Heavy traffic is running ...
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2answers
838 views

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 ...
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1answer
3k views

Poor guest I/O performance KVM Ubuntu 12.04

I have a guest VM running inside a 12.04 Ubuntu host. VM was created using the vmbuilder python script. On the host the phoronix-test-suite "aio-stress" gives a performance speed of >1600MB/s Random ...
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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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1answer
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Linux-KVM / iptables: prevent guest spoofing by matching ip+mac address on bridge?

I have my KVM guests on a standard br0 bridge setup: auto br0 iface br0 inet static address 192.168.1.117 netmask 255.255.255.0 network 192.168.1.1 broadcast 192.168.1.225 gateway 192....
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2answers
3k views

KVM with one host IP and a different subnet for machines

I've already setup a KVM host with proper IP configurations, but my host had me create DHCP and use that to assign the IP's to the machines. I want to see if there's an easier way to do it (or better)....
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1answer
888 views

Is it possible to pass /dev/urandom through from the host to a qemu/kvm guest?

I'd like to pass the host's /dev/urandom device through to a qemu/kvm virtual machine. Note that /dev/urandom is not seekable, so it's not possible to pass it through as a block device using -hda, -...
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1answer
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High I/O latency with software RAID, LUKS encrypted and LVM partitioned KVM setup

I found out a performance problems with a Mumble server, which I described in a previous question are caused by an I/O latency problem of unknown origin. As I have no idea what is causing this and how ...
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1answer
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New KVM guests cannot access outside LAN

I have a KVM host (at 192.168.0.10) that currently has one working KVM guest (at 192.168.0.12). On attempting to install a new KVM guest today, I reached a problem where the network on the new guest ...
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1answer
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Pass an USB hub from a KVM host to a guest with libvirt

I have the following USB devices on a Linux server: # lsusb -t /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/2p, 480M |__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/6p, 480M |...
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4answers
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Slow disk I/O in KVM with LVM and md raid5

I have been battling with a kvm setup under debian for two weeks now, specifically with guest I/O disk performance. The system: -Supermicro 1018d-73mtf (X10SL7-F motherboard) -16GB ECC/UB -Intel ...
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1answer
9k views

How to copy KVM disk image to LVM

Problem I'm getting a No space left on device error when doing a dd command. I'm trying to move a KVM qcow2 file to an LVM partition and thought that the LVM partition needed to be the same size as ...
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3answers
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proxmox KVM routed network with multiple public IPs

I have a dedicated hosting with hetzner. Additionally i have bought a 6IP subnet. My main IP is: 148.111.111.200 My main subnet is: 255.255.255.224 My additional IPs are 148.222.222.1 to 148.222.222....
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1answer
240 views

CentOS7: KVM: error: Cannot create user runtime directory '/run/user/0/libvirt': Permission denied

Been trying to resolve an issue I found by having our Nagios installation use a plugin for KVM, check_kvm, I found. I think my problem boils down to a permissions issue with the nagios/nrpe user. ...
2
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1answer
3k views

virt-install ignoring vnc port/listen?

I'm trying to create kvm machine on remote host. The host is running debian testing. Did use this command: virt-install --name debian-test \ --os-type=linux \ --os-variant=debianwheezy \ ...
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1answer
2k views

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 ...
2
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1answer
2k views

ZFS virtualized on an LVM volume

We've got some large SATA disks kicking around, and I've been toying with the idea of throwing them in a KVM host and installing a FreeNAS VM to manage them. I'd be adding these via LVM to the host, ...
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2answers
1k views

Multiple IP addresses assigned to one KVM VM

System: OS: Debian 6.0 64-bit with KVM installed from packages KVM is managed with Cloudmin 6.4.kvm I have a /29 subnet from my host. The bridge is setup properly for each VM to have its own IP, ...
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3answers
204 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. ...
2
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1answer
5k views

Centos/OVH: public IP on KVM virtual machine

Since a few days, I'm trying to configure my KVM vm to have a public IP address, without any success. First, I'm on OVH, and you need to know they don't allow networking from different mac addresses. ...
2
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1answer
752 views

Why is there a socket interface on the host and a character device interface on the guest for virtio-serial?

I am trying to establish a communication channel between the host and one of its guest virtual machine using kvm as a hypervisor. For this, I am using virtio-serial. To create the virtual machine, I ...
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3answers
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Windows Server 2012 on KVM on Ubuntu 14.04. Runs well for a while and then slows down

I have Windows Server 2012 Essentials running as a VM on KVM running on Ubuntu 14.04 LTS. It performs very nicely after a reboot but after a while it starts slowing down and getting sluggish. This ...
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1answer
2k views

KVM guest time shift on host reboot

I have installed Ubuntu server 12.04 as a KVM host, and created an Ubuntu guest that is also running Ubuntu server 12.04. The servers are in the AST time zone which is UTC + 3 hours. After setting the ...
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1answer
980 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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1answer
482 views

Bad Mumble control channel performance in KVM guest

I'm running a Mumble server (Murmur) on a Debian Wheezy Beta 4 (x86_64) KVM guest which runs on a Debian Wheezy Beta 4 (x86_64) KVM hypervisor. The guest machines are attached to a bridge device on ...
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2answers
5k views

Can not boot CentOS VM using VirtIO in KVM

I converted qcow2 image to raw and changed I/O bus to VirtIO for a VM. now I can't boot that VM. I Installed VirtIO driver with following command: mkinitrd --with virtio_pci --with virtio_blk -f /...
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1answer
2k views

Connecting to a KVM guest OS in Ubuntu

I am lost on this. Basically I am trying to set up a Ubuntu Server 10.10 as a virtual machine by using KVM. Everything went smoothly and I can even sudo-apt get packages from the guest OS. Now, ...
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1answer
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KVM guests lose connectivity after networking restart

we're setting up an ubuntu server 10.04 host with kvm. The host is setup with a bond and bridged interfaces to allow the guests access to the network without natting. Our current configuration is ...
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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 ...
1
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1answer
1k views

Can KVM CPU assignment count differ from physical hosts CPU count?

I have read this question. I knew already that I could for example, have a quad core machine with four guests each having two vCPUs. As they don't all be require 100% CPU usage all the time, the ...
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0answers
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Transparent Bridging of Internal Network in KVM

I am deploying a following topology of virtual Honeynet in KVM.Topology of Honeynet I have two network interfaces eth0 and eth1 ony my System. Problem I am facing is to implement transparent bridge i....
0
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1answer
916 views

Firewall on a KVM host, prevent access to VM:s

I have a Linux machine running KVM with several VM:s, all have public IP:s. For the time being I have everything routed through a bridge (br0) and this works well. I also need a firewall on the host ...
0
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1answer
73 views

How to tell if VM in KVM is using VT-x

I have a machine running under KVM which is not performing very well. I have been trying to google a way to determine if a VM is using VT-x. I can find plenty of links on how to determine if your ...
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1answer
534 views

Access pty login prompt in VM

I have created a VM with virt-install, using as install media a Ubuntu 14.04.01 LTS server ISO. During the installation phase I was connected to the VM via the graphical console. Now I have the VM ...
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0answers
49 views

kvm virtio disk performance scales badly with iozone workload

I'm conducting a number of tests in order understand why some of our workloads generate a really poor "user experience" with db related activities. We have a dl160g9 server with a B140i controller (4 ...
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2answers
1k views

Why VM cannot get the public IP I have from provider?

I have a KVM-Host (on Debian) with root@kvm-host:/# cat /etc/network/interfaces auto eth0 iface eth0 inet manual auto vmbr0 iface vmbr0 inet static address 176.x.y.133 netmask 255.255.255.224 ...
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1answer
181 views

KVM guest has a wrong outgoing ip address

I have a KVM host with a bridge configured on eth0 that has a public ip: auto br0 iface br0 inet static address xx.xx.aa.111 netmask 255.255.255.0 network xx.xx.aa.0 broadcast xx.xx.aa.255 ...
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2answers
2k views

How can I make Windows Server 2012 running on KVM boot with virtio rather than IDE?

I have Windows Server 2012 Essentials running on KVM in Ubuntu 14.04. I've had some problems detailed here Windows Server 2012 on KVM on Ubuntu 14.04. Runs well for a while and then slows down I ...
0
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1answer
610 views

KVM Win 7 Pro + RH virtio net driver

Host: Debian 7.2 x64. Guest Win 7 Pro 32-bit. Virtio disk drivers work flawlessly, but there's a problem with virtio net (netkvm something) drivers. Virtio drivers come from virtio-win-0.1-74.iso. ...
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3answers
3k views

How to makesure VM is in Para virtualization mode on XEN?

I am having a server running XEN,with ubuntu 12.04 as Domain 0. Intel VT is turned on by default and i dont want to run any Windows OS as VM. So 1. how can i makesure that all the created VM will ...
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1answer
78 views

ubuntu kvm disk io slowdown after some tyme

Host system: Ubuntu Server x64 12.04 mdadm raid 1 (/dev/sda /dev/sdb) no lvm dd bs=1M count=256 if=/dev/zero of=filename conv=fdatasync avarage ~ 40 MB/s NCQ on disks is disabled WriteCache is ...
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1answer
1k views

Adding a bridge for my two guests in Debian with KVM

I'm trying to add a two tap0 and a tap1 for my to guests. I'm running Debian with KVM. Each time i restart the server after putting this in /etc/network/interfaces/ the server gets unreachable. Why ...
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1answer
1k views

Debian Squeeze guest running under KVM, how to get serial?

I've just got it running on Ubuntu, have installed everything but the kitchen sink. Got virt-console, virt-manager, running debian Squeeze, everything works. But... I don't want to connect via vnc. ...