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.

Filter by
Sorted by
Tagged with
1
vote
3answers
5k 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 ...
9
votes
6answers
36k 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 ...
0
votes
0answers
11 views

KVM, libvirt, and LVs inside LVs

I have a Debian server running KVM+libvirt. The VMs disks are LVs on the host. The trouble is that if I create LVs inside the guests, they are recursively detected on the host and that creates all ...
1
vote
1answer
34 views

Use Thin LVM Volume for KVM VM

I now we cannot use thin LVM volumes with libvirt. Is there any other alternative allowing use of LVM thin provisioning in KVM/QEMU virtual machines?
0
votes
0answers
12 views

KVM Guests with VLAN interface - limit host access

I am trying to create a KVM server with multiple VLANs for guests, however I only want the host to be routable from one of them. Using CentOS 8. I've currently got one physical NIC (eno1) which has ...
0
votes
0answers
17 views

Is there anyway possible to use a static ip with my host machine and still allow guest VMs to use DHCP?

Here's my case: I'm running 18.04 ubuntu and I have two guest VMs running on qemu/kvm. My machine has a single NIC. I'm using /etc/network/interfaces for this config. My current file looks like this: ...
2
votes
1answer
27 views

How to enable vIOMMU in virt-manager?

I am planning to perform nested virtualization with GPU device. I have guest Ubuntu OS running and I have mapped GPU to it by enabling intel_iommu on the host, and configuring NVIDIA PCI as vfio-pci ...
0
votes
0answers
22 views

qemu-system-x64_86 high CPU comsumption, much higher than the processes inside the guest

I have an Ubuntu 18.04 with several virtual machines running in it using kvm. Using top inside the VM it never goes CPU consumption over 30%, however, if I check the qemu-system-x86_64 processes in ...
0
votes
1answer
23 views

how libvirt cputune config goes to qemu-kvm

I am porting xml libvirt config to qemu executable arguments. Simply I have .xml vm config from virsh edit vm-name and I want to run the same vm machine by executing qemu-system-x86_64 with special ...
0
votes
1answer
86 views

CentOS 7 LibVirt/KVM guest NIC limited 100Mbps/100BaseT

Running a KVM CentOS 7 guest on a CentOS 7 host. Everything is swell except the guest NIC seems to be stuck at 100Mbps. From dmesg: [ 17.217541] 8139cp 0000:00:03.0 ens3: link up, 100Mbps, full-...
3
votes
2answers
751 views

Why does an IPv6 route added before virtual machine is started not work

I have an external server at Hetzner with Debian 7 and trying to setup KVM with IPv6 Routing (the same setup works for IPv4 without problems). I have one Ubuntu Server VM with two interfaces which ...
0
votes
1answer
29 views

How to disable default DHCP on virbr0 and obtain IP from DHCP on host

I have a Ubuntu Desktop, with Libvirt based Virtual Machines setup over virbr0 bridge. Currently libvirt's default DHCP server (dnsmasq) provides IP address assignments. root@ngadre-Inspiron-3542:/...
0
votes
0answers
42 views

why is kvm pool so small

I set up kvm on a fresh install ubuntu server 18.04 on a 1TB disk. There is nothing else on the disk. Whether I use virt-manager or virsh on cli to create a pool, I always get a pool of 3.75GB ...
0
votes
2answers
1k views

iSCSI as KVM storage backend: best practice concerning targets and LUNs per VM

I'm using an iSCSI pool as the storage backend for a couple of virtual machines and I was wondering how other people use targets and LUNs in this use-case. I started out with one target called iqn....
24
votes
4answers
36k views

free up not used space on a qcow2-image-file on kvm/qemu

we are using kvm/qemu with qcow2-images for our virtual machines. qcow2 has this nice feature where the image file only allocates the actually needed space by the virtual-machine. but how do i shrink ...
0
votes
0answers
14 views

Repeated loss of network connectivity to QEMU/KVM/virt-manager VM

I'm having frequent network connectivity failures under the QEMU/KVM/virt-manager stack on openSUSE Leap 15.1. I have a single VM running a software firewall, which is losing connectivity every few ...
0
votes
0answers
19 views

Inter-Guest Network in KVM without a Bridge

I would like to have a psuedo-wire between two guests in KVM. I cannot use a bridge of any type as the guest VMs are actually virtual switches themselves. Conceptually, it seems that a veth-pair is ...
0
votes
1answer
70 views

The portgroup for Network adapter 1, could not be found

I am trying to run RHCSA Lab on MY VMWare Exsi 6.5. after copied my VM file and I have a warning on VMware Exsi "The portgroup for Network adapter 1, , could not be found.It has been assigned to ...
0
votes
1answer
54 views

problems with bridge-networking libvirt on centos 8

I am running a centos 8 as virt-host with libvirt an kvm/qemu. Networking is set to bridge-mode with virbr0. Suddenly and over-night this stops working: The clients don't connect anymore, and if I try ...
0
votes
2answers
2k views

KVM - Access from an external computer to the Virtual Machine

I have the following setup: Notebook (IP: 192.168.1.100) Host: (IP:192.168.1.129) Both Notebook and Host are connected to a router (Internet IP:192.168.1.1)¨ The host (Host) has two virtual machine ...
1
vote
1answer
1k views

kvm guest can not connect to outside of host, vice versa

I have a vmware vm running ubuntu 12.04 server(name=vmhost), with network bridged and full access to the internet. This vmhost is using the kvm hypervisor and is running a vm(centOS 6.4),network ...
0
votes
1answer
1k views

virt-manager connect to kvm w/o password

I want to connect my KVM host with virt-manager, but I use pub key for authentication, and I cant skip the openssh-password popup. Is it possible to log in without a password? (i apologize for my ...
0
votes
0answers
20 views

Routing between linux bridge and openvswitch?

My scenario look like this: As you can see the Node1 use OVS and Node2 use Linux bridge (LB) I need to make both KVM1 & KVM2 can see each other over network. The configuration on OVS I use in ...
2
votes
2answers
440 views

Combine -snapshot and -loadvm snap_id in qemu-system

Is it possible somehow to use -snapshot and -loadvm snap_id together during starting guest by using qemu-system? Currently, if I use these options together, guest can not be started. I need to ...
2
votes
1answer
1k views

capping VM IO with cgroups

I'm using cgroups to cap disk IO that a VM does by using libvirt's support for cgroups. So, I'm getting the major/minor number of the device from a 'ls -lL' on the drive where the '.img' file for the ...
23
votes
9answers
35k 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 ...
0
votes
0answers
31 views

VM in KVM with different network, A can ping B but B can't ping A ? (Bridge KVM network)

I have 2 VM in KVM, and 2 network default and new 1 use defaut network:(virbr0) 192.168.122.0/24 IP: 192.168.122.152. fowarding: NAT the other use new network:(virbr1) 192.168.124.0/24 IP: 192.168....
2
votes
1answer
72 views

Libvirt has no KVM capabilities even though qemu-kvm works

I've learned that CirrusCI offers nested virtualization in their free package for public repos and I am trying to make use of it for testing my Ansible playbooks. Unfortunately, libvirt is insisting ...
1
vote
1answer
2k 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 ...
0
votes
0answers
15 views

host port forward in qemu, defined in machine XML file

I'm trying to get libvirt to port forward to guests without fussing too much with static IP assignments. I found this question with an interesting answer here. The XML section of relevance: <...
0
votes
1answer
2k views

Tap interface within a virtual machine has NO-CARRIER

I am trying to hook up a virtual machine to a host using openvpn. When i create a tap interface within the virtual machine using: /usr/sbin/openvpn --mktun --dev tap1 The state of the tap interface ...
0
votes
1answer
74 views

Nginx closed connection

I 'm getting a lot of lines like these in the error log: [info] 7521#7521: *1061 peer closed connection in SSL handshake while SSL handshaking, client: 198.41.231.201, server: 0.0.0.0:443 [info] 7521#...
0
votes
0answers
47 views

libvirtd domain doesn't start with image on smb share

I virtualized a Windows server with libvirtd that uses an additional image on a smb share. The host system was Fedora Server 30 and everything worked fine. Now I have upgraded the host to Fedora ...
0
votes
1answer
1k views

enable vnc after virt-install

I've created a virtual machine using virt-install with graphics --none. I want to enable vnc. I've tried virsh -c qemu:///system qemu-monitor-command vm171-SC-1 --hmp change vnc :3 but it doesn't ...
2
votes
1answer
80 views

How can I make my libvirt/KVM guest see all IPv4/UDP multicast traffic?

I have an issue with IPv4/UDP multicast traffic not being fully visible from within a KVM guest. The guest has a dedicated NIC which is attached using MacVTap. Both the host OS and the OS in the ...
1
vote
1answer
109 views

CentOS 7, KVM, bridge, VLAN, bond and no guest traffic

I'm running into an issue where my KVM guests have no network traffic in- or outgoing. After a lot of hours debugging I'm pretty sure I'm missing something essential. What I have a server with 2 10 ...
0
votes
0answers
29 views

Proxmox/KVM Bridged networking breaking ssh connection

I'm running into an issue with Proxmox/KVM. I have setup a second bridge (vmbr1) that covers the IP space 172.16.1.0/24. I have assigned 172.16.1.1 to vmbr1. The vmbr1 is setup according to this. I ...
0
votes
0answers
12 views

qemu-kfm LVM logical volume size inconsistency in df output

The Problem: andi@docker-host-01:~$ df -hT . Filesystem Type Size Used Avail Use% Mounted on /dev/vdb1 ext4 79G 41G 35G 55% / Adding 41G & 35G gives 76G and not 79G as shown ...
14
votes
1answer
5k views

KVM guest cannot write to 9p share owned by non-root

I am aiming to set up full write access to a 9p share for a KVM guest. Both host and guest have the same users/groups with the same IDs. Both host and guest should be able to write to the share using ...
0
votes
1answer
107 views

Virsh command not working to install Centos 8 virtual-machine on Ubuntu 18.04 via qemu/kvm [closed]

I am trying to install centos 8 on ubuntu 18.04 as a virtual machine. I have a wireless connection. When I run the following command: chh2@chh2-cpu:~$ sudo virt-install --name=chris_centos --ram=...
17
votes
2answers
12k views

Is KVM a type 1 or type 2 hypervisor? [closed]

Is KVM a type 1 or a type 2 hypervisor? I understand that type 1 hypervisors run on bare metal while type 2 hypervisors are applications running on top of an operating system (such as VMware ...
0
votes
1answer
2k 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 ...
0
votes
1answer
79 views

KVM-QEMU bridged network not working - guest can only access host

I am trying to configure VMs to act like devices on my LAN, instead of hiding behind the host. This is the tutorial I followed: RHEL8 Network Bridged Interface My router/DHCP is at 10.10.1.254 Host ...
0
votes
1answer
2k views

KVM guest clock sync with host

I'm running KVM w/ centos 6.x. My guest vm clocks are booting with a 1-2 second lag from their host. My clocksource for the host is ntp. My clocksource for the guest is "kvm-clock", but I need to ...
39
votes
5answers
68k views

Correct way to move kvm vm

I'm wondering what is the correct way of moving a VM between two KVM hosts without using any kind of shared storage Would copying the disk files and the XML dump from the source KVM machine to the ...
0
votes
0answers
15 views

OVirt 4.2 Lost Connection To Nodes

I'm using OVirt version 4.2.3.8-1.el7 connected to 2 IBM PureFlex servers with 10 nodes (5+5) in total. OVirt suddenly lost connection to all the nodes but the VMs in these nodes are working without ...
1
vote
1answer
2k views

Connect KVM virtual network to internet

I have a CentOS server running KVM and need to connect a virtual network to the internet. The network must be routed or NATted, it must not be bridged (port security). If possible, I would like to ...
1
vote
1answer
1k views

Limit linux file cache memory usage (to avoid hypervisor memory exhaustion)

I have a server with 16GB RAM running several linux virtual machines (around 10), which perform several different tasks. These machines, with the default configuration, will fill up the memory I give ...
2
votes
2answers
6k views

Backup of KVM raw-images

I'm running qemu-img-0.12.1.2-2.355.0.1.el6 on CentOS 6.3 using raw images for my virtual machines. Is there any way to safely backup guests, without stopping them? I've tried to make snapshot on a ...
0
votes
1answer
207 views

Virt-Manager shared folder Linux host Windows guest

I have a Manjaro Linux up-to-date host with a KVM Windows 10 guest with SPICE guest additions installed managed through Virt-Manager. I'd like to be able to access the host via a shared folder on the ...

1 2 3 4 5 41