libvirt is an API and toolkit for developing applications which manage virtual machine hypervisors, the virtual machines running under them, and virtual machine storage.

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17
votes
3answers
23k 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
1answer
18k views

KVM and Libvirt - How do I hotplug a new virtio disk?

I am trying to hot-add a file-based disk to a running KVM virtual server. I've created a new disk from scratch using the command dd of=/home/cloud/vps_59/test.img bs=1 seek=5G count=0 and I was ...
15
votes
4answers
10k 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.
13
votes
2answers
6k views

Linux containers (LXC) on Red Hat/CentOS EL6 - lxc-create versus libvirt?

It's tricky trying to stay within the good graces of Red Hat and still plan for system longevity... I've been a proponent of Linux Containers (LXC) for over a year. My initial installations were ...
11
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 ...
11
votes
1answer
5k views

Read/write access for passthrough (9p) filesystems with libvirt/qemu?

I have recently started experimenting with the support for passthrough filesystems in recent versions of KVM/QEMU/libvirt. Making the filesystems available for read access has "just worked", but I'm ...
9
votes
4answers
4k views

How to keep time on resumed KVM guest with libvirt?

On my host I am using libvirt and a KVM guest. When the host is shutting down, libvirt suspends the guest. When the host is starting up, libvirt resumes the guest. The problem is, if the guest is ...
9
votes
5answers
2k views

libvirt: Change dhcp-setup without restarting

I'm using libvirt and kvm to virtualize my server. I configured libvirt to start a dhcp-server on the bridge-network-interface to give the vm's their ips. Every VM's gets always the same ip based on ...
8
votes
2answers
268 views

Can i pause VM's while power-cycling iscsi storage array

Unfortunately I may have to power-cycle my storage array. In the context of using KVM with libvirt managing the Virtual Machines where i need to power-cycle the storage array, is it possible or even ...
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 ...
8
votes
2answers
8k views

Monitor VM's resources (CPU, RAM etc)

I'm testing Openstack and i'd like to know how can i find out about resource utilization inside instances (Virtual Machines). Openstack uses kvm, qemu and libvirt in my testing environment. Is there ...
8
votes
3answers
349 views

Technology for short-lived private VMs

I'm trying to build a system that will run short-lived (CI and test builds) of software components, it's mandatory according to my requirements that each live on a private host. I'm taking that ...
7
votes
1answer
2k views

How do I make a persistent domain with virsh?

virsh create somefile.xml creates my machine just fine but when I shut the machine down the whole thing disappears. Machines I made with the virt-manager GUI are persistent (stick around after ...
7
votes
7answers
8k 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 ...
7
votes
1answer
9k 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
12k views

Changing boot device for a QEMU-KVM virtual machine

I am trying to change the boot device for a VM. I go to the VM's XML file in /etc/libvirt/qemu and set <boot dev='cdrom' />. Still, it attempts to boot from the harddrive instead of the cdrom. ...
7
votes
4answers
2k views

Using virt-install and http preseed to do unattended ubuntu 10.04 install

The virt-install command line I used is below sudo virt-install kvm ubuntu -v sudo virt-install -v -n golden-egg -r 256 --disk path=/var/lib/libvirt/images/golden-egg.qcow2,size=5 --os-type ...
6
votes
1answer
51 views

Prevent hijacking IPs in KVM/libvirt

How can I prevent a VM user/client from accessing IP addresses he doesn't own but are routed over the same bridge on KVM/Libvirt? IP addresses are routed to a cisco switch vLan consisting of a /24 ...
5
votes
3answers
4k views

libvirt: how can I make a domain start when the host starts?

I would like some of my domains to start automatically when my host starts (I'm using libvirt+KVM on ubuntu). I guess I could put some "virsh start..." statements in rc.local, but is there a way to ...
5
votes
2answers
6k views

Routing networking on kvm

There are a lot of configuration used for Kvm-networking. But i'm not able to get to the guest from the host or outside. I'm working on Ubuntu 11.04. On the guest i've a WindowsXp with dhcp. I want ...
5
votes
2answers
8k views

optimal settings for win7 64 guest on kvm 64 host managed with libvirt

I am using libvirt to control kvm on a fairly new (core i3) host running Debian Squeeze amd64. The Host as well as Linux guests work and feel fast and responsive. Simply installing Win7 with ...
4
votes
2answers
9k views

kvm low io performance

performance of my setup is quite good (geekbench, how it 'feels', ...) even disc throughput (libvirt on raw lvm-partition) is very close to the raw performance on the server) but IOP/s are as low as ...
4
votes
1answer
18k 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 ...
4
votes
1answer
16k views

How to convert a raw disk image to a copy-on-write image based on another image for use with kvm and virt-manager?

I have a virtual Windows machine running on kvm. Presently it has a 90GB raw disk image. I would like to clone this VM without having to keep two copies of the 90GB raw disk image around. It seems ...
4
votes
5answers
2k views

Web-Based Virtual Machine Manager

I am looking for a web-based virtual machine manager, which will work on our Ubuntu server. Ideally, I need something that our team can use to create a VM, test builds and packaging and then either ...
4
votes
2answers
4k views

Change VNC listen address in Libvirt without restarting VM

Is there a way to to edit the listen address of a Libvirt-Machine on the fly? At the moment it seems like when I want to edit the listen address, I have to shut down the corresponding VM first, then ...
4
votes
2answers
3k views

qemu-kvm/virsh: No network connectivity whilst using bridged networking

I'm having an issue with performing virtualisation via libvirt/qemu-kvm, in which my set up for bridged networking doesn't appear to be working correctly. I've followed every tutorial I can find and ...
4
votes
1answer
578 views

libvirt guest cannot reach outside world

My server connects to the public internet via eth0 (50.131.xxx.xxx). The same server connects to the LAN via eth1 (192.168.138.1 on 192.168.138.0/24) On the same server, I run libvirt, which created ...
4
votes
1answer
3k views

Poor network performance with KVM (virtio drivers) - Update: with vhost_net

I've set up several KVM based networks before, and never encountered this issue, can't for the life of me think what I'd have set up differently previously. Setup Basically, Ive got and entirely ...
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 ...
4
votes
1answer
182 views

Network filtering with libvirt + xen + bridge + nat?

How can I properly add basic network filters (clean-traffic or, at least, ip-spoofing prevention) to XEN (xend) guests managed by libvirt? Or, in particular, can I manually execute libvirt's ...
3
votes
2answers
10k views

KVM/libvirt: How to configure static guest IP addresses on the virtualisation host

What I'd like to do is to set the guests' network configuration (IP address, subnet, gateway, broadcast address) from the host system. The used network setup is in bridge mode. How can I configure the ...
3
votes
4answers
7k views

libvirt network error - no 'default' network device found

My original purpose is to create centos image for openstack. Although I did directly with kvm, still wondering about error. Was using this manual for my task. After this command: # virt-install ...
3
votes
3answers
616 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 ...
3
votes
2answers
5k 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 ...
3
votes
1answer
3k views

Bandwidth monitoring on KVM

Is it possible to monitor/limit bandwidth for KVM guests? I'd like to give people VMs on my server but I want to be careful not to go over my monthly bandwidth limit. The only places I can find that ...
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: ...
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 ...
3
votes
1answer
160 views

Qemu+libvirt+kvm significant performance lag in VM's

I am troubleshooting poor performance on our new VM host machine which is a Dell PowerEdge R415 with hardware RAID. We've got about 20 VM's running like this: qemu-system-x86_64 \ -enable-kvm \ ...
3
votes
1answer
2k views

How to replace QEMU binary with newer version for libvirt live snapshots

This is my first post, so please be gentle. :) My CentOS 6.5 box has a QEMU binary that does not support live external snapshots. This is the command I attempt on the virsh CLI, and its output: ...
3
votes
1answer
416 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
votes
1answer
493 views

libvirtd kvm networking on Centos5.4

I've got KVM installed on CentOS 5.4, and am attempting to set up a virtual network to allow each VM to communicate with services on the host, namely DHCP to allow PXE boot installations. I'm having ...
3
votes
2answers
822 views

How to setup IPTables on KVM host - iptables-persistent is being ignored

I'm trying to setup some specific IPTables rules on an ubuntu 14.04.1 host that runs some KVM guests. The box has multiple NICs with multiple IP addresses and the guests use different addresses based ...
3
votes
3answers
734 views

libvirt + ESX (HTTP response code 400 for call to 'Login')

I'm trying to connect to a vSphere cluster using the information from the libvirt documentation. $ virsh -c "vpx://root@10.51.4.11/dc1/dc1-cluster-e01/dc1-vsphere-e04/?no_verify=1" Enter root's ...
3
votes
1answer
8k views

virt-manager can't open the display

My virt-manager was working just fine and all of a sudden stopped working, throwing in error: RuntimeError: could not open display root@rakcal ~]# echo $DISPLAY localhost:10.0 [root@rakcal ~]# ...
3
votes
1answer
1k views

Virt-manager: unable to open a connection to the libvirt management daemon

I'm having a bit of trouble connecting to my virtual machine host, which is an Ubuntu server running KVM/Libvirt. I can connect to the server using an Ubuntu client and I can connect via virsh on a ...
3
votes
4answers
4k views

KVM-Guest does not boot: qemudParsePCIDeviceStrs

I have a Server running Ubuntu 10.10 Server-Edition kvm, and libvirt (both ubuntu-native packages) HDD-Partitioning was done with LVM. Then I created some VMs with Virt-Manager and assigned ...
3
votes
2answers
1k views

How do I run a stable Windows XP kvm guest on Ubuntu 10.04?

I have three Windows XP guests running on a recently upgraded 64-bit Ubuntu 10.04 system. Occasionally (on the order of once every few days), one of the guests will become non-responsive and the kvm ...
3
votes
1answer
2k views

Remote automated provisioning to a XenServer Hypervisor

I'm currently working on a project where I use Vagrant with Ansible provisioning to create local environments in VirtualBox. I'm currently working with a University and we have a XenServer Hypervisor ...
3
votes
1answer
247 views

2xAMD Opteron 6128 with libvirt, Physical CPU 13 doesn't exist

I need help with libvirt(?) problem. Server specs: ProLiant DL165 G7 2x AMD Opteron(tm) Processor 6128 System: Debian GNU/Linux testing (wheezy) 3.2.0-3-amd64 libvirt 0.9.12-5 kvm ...