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.
588
questions with no upvoted or accepted answers
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 ...
4
votes
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 ...
4
votes
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 ...
3
votes
0answers
165 views
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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
votes
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 ...
