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.

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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 ...
4
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0answers
1k views

Libvirt & USB Hub Passthrough

I have a virtual machine which I wish to have a USB Hub and all of its devices allocated to a virtual machine. The Hub in question is a USB hub which itself is plugged into one of the ports on the ...
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3answers
9k views

Promiscuous mode in KVM

I have cloud system based on Openstack Icehouse-version. Now I want to test newer version of Openstack (Juno) inside my existing cloud. All hosts and guests use Ubuntu 14.04 as their OS. KVM is ...
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Connect from Windows host to QEMU inside Docker

I am trying to establish a connection between Windows 10 running Docker container (Linux), which runs QEMU to host a QNX OS. This picture should make it more clear: Structure I would like to ...
3
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1answer
415 views

should multiple threads be spun up by kvm/virtio-scsi on the host during IO workload

I am trying to pass-through a scsi lun to guest for best performance. What I am seeing on the host is that with iodepth=64 - 64 threads of qemu process are spun up for the VM. I believe this causes an ...
3
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0answers
409 views

KVM: What is stored in var/lib/libvirt/qemu

My Question is "What is stored in the /var/lib/libvirt/qemu folder?" Is this used as somekind of backup folder ? Backgroundinformation: I have a Debian Server with a running KVM installation(+libvirt)...
3
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0answers
339 views

Convert qemu syntax to virt-install or virsh xml

I have parameters for qemu-system-x86_64, which attach unix socket as interface into VM: qemu-system-x86_64 -chardev socket,id=char1,path=/tmp/sock0,server \ -netdev type=vhost-user,id=...
3
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0answers
862 views

Qemu packer ssh failed connection reset by peer

I am trying to get packer to create a qemu/kvm image. I feel like it should be fairly straightforward but my build keeps failing on ssh. Here are the relevant files template.json: { "builders": [ { ...
3
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0answers
2k views

QEMU USB passthrough is not working

I stuck at getting USB passthrough working with Windows 8.1 guest OS on Ubuntu Server 14.04. I started by installing qemu using the Ubuntu Documentation (https://help.ubuntu.com/community/KVM). The ...
3
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0answers
847 views

KVM NIC passthrough “device already in use”

I have a server with 2 NICs 01:00.0 Ethernet controller: Intel Corporation Ethernet Controller 10-Gigabit X540-AT2 (rev 01) 01:00.1 Ethernet controller: Intel Corporation Ethernet Controller ...
3
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0answers
3k views

Please help recovering lost volume group

After a reboot, the volume group on my server completely disappeared. [root@dal01 log]# vgdisplay No volume groups found [root@dal01 /]# lvdisplay No volume groups found [root@dal01 ~]# pvdisplay (...
3
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0answers
823 views

How to configure opennebula for allowing a cluster private network to host images with public IPs

I am installing open nebula 3.4.1 for running virtual machines a (kvm based) cluster made of 5 computers: a front-end machine having 2 network interfaces and 4 slaves machines with a single network ...
3
votes
1answer
725 views

KVM guests are very slow after host upgrade to Debian Squeeze

Yesterday I upgraded a Debian Lenny server to Squeeze. This server hosts two KVM guests. One has run Debian Squeeze itself all along, the other was originally Debian Lenny, upgraded to Squeeze the day ...
2
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1answer
77 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 ...
2
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0answers
43 views

I'm getting error during HA configuration for KVM on CentOS

After adding all nodes and resource agents in my cluster I'm getting this error please someone suggest me something. Please take a look in the image-
2
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0answers
69 views

QEMU-KVM bug: guest interface locks up a core with soft interrupts

Bug: I have a qemu-kvm on Ubuntu (host 14.04.5 LTS 3.13.0-95; cannot upgrade; , guest Ubuntu 18.04.03 LTS 4.15.0-65) Guest has two network interfaces, directly (VEPA) connected to two separate host ...
2
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0answers
462 views

Configure netplan to use a different interface for bridge

I'm setting up a virtual machine host on Ubuntu 18.04.3. I installed KVM and have succesfully set up a qemu vm which connects through a bridged network. It shows up as a regular machine in my network. ...
2
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1answer
74 views

QEMU - how to setup vlans after they have been deprecated and removed

Until I updated my OS, I could launch VMs with the following network configuration: -net nic,vlan=0,model=virtio,macaddr=${MAC1} -net bridge,vlan=0,br=${BRIDGE1} \ -net nic,vlan=1,model=virtio,...
2
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0answers
115 views

How to fully emulate VM hardware?

How do I fully emulate, pass through, or spoof all the hardware for a virtual machine? I want to set up a few guest VMs in such a way that they do not have any special drivers or odd hardware info. ...
2
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0answers
692 views

XP KVM stuck at “Booting from Hard Disk”

Just to see if it could be done (and if so, move other physical XP machines to VM environments), I took the hard drive out of a decommissioned laptop, captured a WIM of it, and applied it to a QCOW2 ...
2
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0answers
639 views

Kernel panic when booting qemu virtual machine

I usually install template virtual machines on a dedicated server and then copy the disk to other production servers. It has worked for years and still works today in all cases but one. I have ...
2
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0answers
145 views

Is it possible to capture traffic on host when using KVM passthrough?

I have a KVM guest which uses PCI passthrough for its network interfaces: <hostdev mode='subsystem' type='pci' managed='yes'> <source> <address domain='0x0000' bus='0x05' slot='...
2
votes
1answer
584 views

centos 7 kvm error trying to guestmount qcow2 image

I have a CentOS 7 KVM host. A partition on one of the VM's seems to be corrupt. Image is qcow2. When trying to mount the image to troubleshoot I receive the following error: [root@vmhost02 images]# ...
2
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0answers
350 views

Frequent page allocation failures on a KVM

Lately my server has been going down quite often. It happens almost every day early in the morning. Looking at the syslog, I found a lot of these: Oct 11 06:51:12 pleskvm kernel: [1895007.359087] ...
2
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0answers
388 views

How to provision DRBD to libvirt storage pool?

I want to expose DRBD replicated storage (2 nodes Active/Passive) to libvirt as a storage pool for qcow2 files. However, I have the following error message: virsh pool-create-as qcow2 --type=logical -...
2
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0answers
2k views

KVM/QUEMU guest slow disk performance

I'm really confused of QEMU/KVM behavior. I have a server - about 100GB RAM, 2 CPU - 6 core + HT, and three HDDs - one for root, and two for BTRFS-mirror for virtual machines (HGST HDN724030ALE640 if ...
2
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0answers
80 views

Convert VM (redhat virtualization 3.5) to a physical server

I have a virtual machine running on red hat virtualization 3.5, i need to convert that VM to a physical server. (mainly due to a performance issue) my volume groups as follows NAME ...
2
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0answers
2k views

Ubuntu KVM - Can't access network through bridge from guests, no DHCP, no ping

I have a laptop running Ubuntu 16.04.3 LTS graphical (so has Network-Manager et al installed). I think I've got KVM and QEMU installed correctly. When trying to set up a Debian VM from the netinstall ...
2
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0answers
571 views

Ubuntu KVM virsh console domain connects, but does not load console

I installed a copy of Ubuntu 17.04 using virt-install, on my server (non desktop). sudo virt-install --connect qemu:///system -n wiki -r 4096 --vcpus=2 -f /dev/mapper/vgpool-wiki --network=bridge:br0 ...
2
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0answers
2k views

Linux KVM QEMU Host with high CPU load

I have a machine running Ubuntu 16LTS with KVM/QEMU for a hypervisor. It has 1 guest running right now (A Ubuntu Server) that is using less than 1% of it's CPU and about 100MB of the 1000MB RAM ...
2
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0answers
2k views

No network connectivity in KVM guest

I'm attempting to set up my first guest set up under KVM and am having trouble getting the network working. The host machine "vm_host_box" has a static IP of 4.4.4.185. The guest I am setting up ...
2
votes
1answer
758 views

(KVM on Centos 7) Cannot ping to Guest or vice versa with single NIC Host

I have single NIC Host on Centos 7, which I want to make virtualization using KVM-Qemu. HOST The Host IP is 192.168.1.110 and the interface is enp0s31f6 I have deleted the "default" NAT ...
2
votes
2answers
239 views

Bridged routing with KVM and independent IP addresses

I have a dedicated Server (at Hetzner), with Debian Jessie and und KVM for virtualization. For the two Virtual Machines I have two additional IP addresses (with extra MAC addresses), which are not ...
2
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0answers
470 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 ...
2
votes
1answer
600 views

Routed bridge networking for KVM guests along with eth1 alias interfaces for shared hosting with dedicated IPs for each virtualhost

First question here on serverfault, so kind of a newbie, all feedback is welcome. I have a dedicated server running Debian GNU/Linux 8.4 (jessie) with one public IP and multiple additional public IPs ...
2
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0answers
3k views

Linux swap partition not mounted by systemd on boot after dist-upgrade

Recently, I performed a dist-upgrade from Debian Wheezy to Jessie. The upgrade was performed without any error but after the upgrade the swap partition was no longer mounted/activated. The mentioned ...
2
votes
1answer
971 views

How can I reconfigure a Linux guest in Proxmox to use a virtio-based HDD instead of IDE?

I'm running Proxmox 3.3.1 to host a virtual machine running Linux (64bit, kernel version 3.2.0). The virtual machine uses a 512GB HDD which was unfortunately configured to use the ide driver when ...
2
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0answers
1k views

Proxmox/KVM: Can not clone VM

I would like to create a clone of a KVM machine - yesterday I was able to create a clone of the same machine within some minutes. Now it takes hours and is still stuck an "0%": create full clone of ...
2
votes
1answer
321 views

vlan qemu: guest listening from other guests

I'm trying to simulate a little network of 3 machines using QEMU where a machine (deb1) is directly connected with the host and the other 2 machines (deb2, deb3): Host ...
2
votes
1answer
719 views

XFS/EXT4: Why is actual file size on disk larger than apparent size? Clarification

On a CentOS 7.1.1503 (3.10.0-229.el7.x86_64) system running KVM/qemu on an XFS filesystem, I'm attempting to work out what specifically is adding additional space to a VM diskimage file. $ ls -ls --...
2
votes
1answer
943 views

Creating a virtual network for KVM guests spanning multiple host machines

I have 5 physical machines running Ubuntu 14.04, all of them are together in a network. These all have static IP addresses. Each of these machines has 1 to 4 virtual machines via KVM/QEMU running ...
2
votes
1answer
1k views

Create KVM storage pool using a ext4 formatted drive

I have a secondary hdd that I would like to use as a storage pool for my KVM host. Here is the xml file I use to create the storage pool, <pool type='disk'> <name>guest_images_disk<...
2
votes
1answer
900 views

Ubuntu 12.04.2 LTS Server - Randomly hangs with no logging

My server randomly hangs and becomes unresponsive without any logging (dmesg, syslog, kern.log, boot.log, and messages). I cannot predict when it is going to happen. Sometimes the server runs fine for ...
2
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0answers
2k views

How Open-VSwitch bridge assigns IP addresses to guest when used on KVM hypervisor?

I have setup ovs switch on ubuntu and configured network xml and guest VM xml files respectively(Set-up for KVM hypervisor). Created new network for openVswitch by creating and defining new vlans.xml ...
2
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0answers
628 views

Infiniband + KVM

this question is a copy from stackoverflow, as I was told, my question would fit here better. Despite quite a long search for days, I could not find any good information about the following - though ...
2
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0answers
1k views

libvirt / kvm guests take very long time to start after host reboot

Host system is CentOS 6.5 x86_64. I have setup an Ubuntu guest by following this wiki. The guest works, but: if I reboot the host, it takes a very long time (about 30 minutes on the last reboot) ...
2
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0answers
175 views

“Nosy Neighbor” and the CFQ scheduler

I'm trying to understand how does using CFQ affects the "Nosy Neighbor" problem. I'll ask it a bit naively, can a "Nosy Neighbor" even exist when using CFQ? Isn't that CFQ should make sure all ...
2
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0answers
778 views

How do I get IPv6 packets to my KVM virtual machine?

My setup is: Debian Wheezy x64 on the host and on the guest. I am using a tun/tap setup to connect a virtual machine to the host. The KVM network options I use are: -net nic,macaddr=DE:AD:BE:EF:1A:...
2
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0answers
436 views

Exchange 2010 on KVM - CPU usage reporting incorrectly

Good Morning, I have virtualized an exchange server using KVM (proxmox actually). It is Exchange 2010 SP3 running on server 2012 R2. KVM version 1.7.1. I am using the latest (0.1-74) virtio ...
2
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0answers
442 views

Selenium in virtual machine is slower than desktop

I've set up a kvm virtual machine, CentOS 6 on both guest and host. I'm using selenium on the guest in order to test a web site. However, it loads significantly slower than trying to hit the web site ...

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