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, ...

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Turn off output/force DPMS on unloaded GPU without driver

I'm running a KVM VGA Passthrough VM on my desktop, passing it my dedicated GPU. This VM does not automatically start as I don't always need it. When the VM isn't running, my desktop doesn't touch the ...
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1answer
16 views

same libvirt config, one machine boots, the other does not

I am migrating a bunch of vms from an old machine to a new one. The old one was using some in-house scripts and lvm logical volumes, the new one uses libvirt and plain files. The configs are rather ...
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0answers
9 views

Installing VirtIO SCSI on Windows Guest fails

I'm running Windows 10 as guest via KVM / qemu. Unfortunately, Windows doesn't recognize the fedora virtio drivers I want to install for better HDD perfomance. The driver itself does show up, but ...
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14 views

Virsh - How to create multiple clones of a single volume

Is it possible to create multiple clones of a single volume? Whenever I try cloning a volume multiple times, at the same time it creates the error Requested operation is not valid: volume ...
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21 views

NATted host cannot talk to itself unless virbr0 is in promiscuous mode

We have the following situation: A hypervisor using KVM-Qemu/libvirt with a single VM. The VM has the internal IP 192.168.122.151 on the default network pool using virbr0 on the hypervisor. We've ...
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12 views

Migrate Virtual Machine from KVM to Xen

I'm trying to migrate a Virtual Machine from Qemu KVM to Xen Hypervisor 4.1, but have problems with it. What is the best and simplest way to do it? What I've done so far: I have installed ...
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2answers
3k views

Very strange file size (more than 600 PB) on a small filesystem

I had a file on an XFS filesystem which size was about 200 GB. It was a QCOW2 image containing a virtual disk of a KVM-driven virtual machine. Something went wrong (maybe it was some glitch of ...
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1answer
25 views

How to create virtual networks by using libvirt?

I have installed qemu/kvm and have tried to create some virtual machines and network them together. What I would like to achieve is 2-3 virtual machines in their own private network (e.g. ...
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8 views

Do I need acpid daemon in virtualization guest?

I get VPS with KVM virtualisation (server for hosting services). I remove most of desktop services (like dbus, consolekit, xorg) because of security and stability concern. Guest run on virtualised ...
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0answers
10 views

virt-manger cannot access VM disk

On a Centos 6.7 I have installed kvm and created a vm with a 30G virtual disk located in /var/lib/libvirt/images/vm1-disk. I created another disk with the following command: virsh vol-create-as ...
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17 views

Add new subnets to KVM Host

I need to assign a handful of /27 subnets to my KVM host node (Centos 6). I routed them correctly at the Cisco switch, so that's all go. Traceroute & ping works fine on gateway on each subnet, ...
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25 views

How to do remote calls from server A to B to create virtual machines

This is my first question on serverfault so I hope I'm doing this right as I'm usually on Stackoverflow :-) I have two Ubuntu 14.04 LTS servers, server A and B. Server A runs the web server where ...
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33 views

Hardware raid, LVM and KVM cache policy

I have a question about right cache policy for KVM using LVM and hardware raid-controller. So from the bottom: 1. We have LSI RAID controller 9260, 512Mb cache and BBU. Later we also will have ...
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0answers
18 views

Libvirt does not see updated LVM volume

All VMs run off an LVM pool. I resized one of the LVM volumes to increase VMs drive copacity. Resized it with lvextend as usual. Everything is successful and lvs shows the new size. Libvirt does not ...
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0answers
21 views

Java application is slow in virtual server (KVM)

I have a Java web application, which runs from JAR, starts embedded Tomcat and is using Spring Boot. Problem is that it runs very slow when running in KVM virtual guest. The same application in the ...
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0answers
15 views

How does Qemu handle memory?

I'm having a real hard time understanding something and I was wondering if anybody has any experience with this and is able to help. I have two KVM VMHosts, one running qemu 2.4.1 and the other ...
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0answers
22 views

How to completely migrate Windows Server VMs with no access to hypervisor?

There are two Windows Server VMs (2008R2 & 2012R2) hosted on OVH (via VMware I think). I would like to move away both VMs from OVH to my server running KVM VMs. OVH isn't going to give me any ...
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0answers
19 views

How do I properly configure KVM

I have a remote dedicated server on which I have installed KVM. When trying to create my first virtual machine I am unable to ssh to the machine. I assumed that I needed another ip address so I ...
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1answer
24 views

Correct virtio setup on Ubuntu 14.04 64-bit host

At the present moment, my guest is running inside qemu and host is kvm intel, running Ubuntu 14.04, kernel is 4.3.0 stable. From within the guest, when I run "hdparm -i /dev/sdb" on the guest, I ...
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41 views

How slow can be a QCOW2 vm disk (proxmox/KVM) over NFS (dedicated 1Gbit)?

I'm running 3 proxmox 3.4 nodes using NFS shared storage with a dedicated 1GB network switch. root@lnxvt10:~# pveversion pve-manager/3.4-11/6502936f (running kernel: 2.6.32-43-pve) root@lnxvt10:~# ...
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0answers
19 views

How to create a new domain from an existing base image in virsh

Is there a way of creating a domain with virsh from a base image? I have looked around and found that it is possible using virt-install, however I would prefer it if this was done purely through ...
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0answers
17 views

Assign a large subnet of IPs to KVM Guest VM

I have KVM host node running a few VMs. I create them using SolusVM panel, however they don't have an option to add bulk IPs in one shot to a guest VM which is silly. I'd like to know how I can add a ...
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0answers
18 views

how to assign failover ip into windows vm (ubuntu, kvm)

I purchased a dedicate server (Ubuntu 14.04 LTS amd64) with a failover ip from online.net. And i want to setup a windows vm with failover ip using kvm. I tried myself several times, but all failed. ...
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1answer
28 views

Debian server can't connect to outside world and vice versa

At some point within the past 48 hours my KVM server, which had been running without issue for 6 months, went down completely and was unreachable. Using the control panel to my server, I saw that the ...
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1answer
16 views

Is a QEMU installation on a raw disk backward compatible?

I create a qemu image like this: qemu-img create -f raw my_disk.raw 2G and (manually) install debian into it: qemu-system-i386 my_disk.raw -enable-kvm -m 1024 -cdrom my_debian_cd.iso Say I do ...
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0answers
29 views

CentOS 7 machines can't ping each other over ipv6

I got three machines configured for ipv6: CentOS 7 vm1 - 2602:306:cc2d:f591::a/64 CentOS 7 vm2 - 2602:306:cc2d:f591::b/64 Macbook - 2602:306:cc2d:f591::c/64 The two VMS are on the same host (a ...
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0answers
22 views

Linux / Proxmox KVM machine boots unreliable after migrating to other server

I have a KVM VM running on a Proxmox 2.3 server. The Guest OS inside the KVM machine is an Ubuntu 12.04 LTS 64 bit. I took a consistent backup of the VM (Proxmox VE backup function) and restored the ...
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0answers
42 views

FreeBSD 10 guest on qemu/kvm CentOS 7 host

I'm trying to install FreeBSD 10 on CentOS host without using graphics (using only serial console). I've tried: # virt-install -n freebsd-a -r 512 --vcpus=1 --os-variant=freebsd10.0 --graphics none ...
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38 views

Use a /29 block on a Hetzner KVM Setup

I have been trying to assign the IP's I got from this 5.9.192.32/29 block. I have followed every step in this tutorial, but I end up with no connectivity on the guest VM's. My Host configuration ### ...
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46 views

Routing host traffic through Linux KVM (pfSense) router

I have a pfSense virtual machine running on a CentOS 7 host. The host has 2 network adapters, enp1s0 and enp3s0. enp3s0 is connected to a bridge br1. My pfSense virtual machine is also connected to ...
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1answer
35 views

Linux server, setting up VM with different IP

I just purchased a dedi server (Ubuntu 14.04 LTS) & additional IP's (called Failover IP's) from OVH. I want to setup a KVM virtual machine in order to for them to have their own independent IPs. ...
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0answers
28 views

ping from internal to external side of gateway doesn't work until one ping from gateway to internal-client

I managed to create isolated network in KVM-QEMU virtual environment. There is a gateway-pc virtual machine which should connect between isolated network and my LAN with dnsmasq installed on this ...
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0answers
51 views

KVM bad IO sync performance in Linux guest

I'm setting up virtualized Ubuntu 15.10 guest inside Ubuntu 15.04 server using libvirt and KVM. Storage in host system: # mount | grep ext4 /dev/sda1 on / type ext4 ...
1
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1answer
24 views

Use Lvm snapshot for a new (KVM) virtual machine

I need to migrate one CentOS5 (32bit) physical server to in a virtual machine. My idea is to take a snapshot of the LV and then import in kvm creating a new vm. Is this a good idea? More precisely, I ...
2
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1answer
50 views

Handling /etc/fstab when upgrading linode from Xen to KVM

I have a linode that is currently on one of Linode's Xen servers. I see that I am eligible to upgrade to a KVM linode. One thing that concerns me is that Linode's upgrade guide says block devices ...
2
votes
2answers
146 views

KVM top shows high CPU load on host for windows7 guest though windows is on idle

we have an virtualization environment with actually 4 VMs (2 x linux, 1 x w2k3, 1 x win7). In the host system (Debian Jessie) top always shows a CPU load of 30-70% (or more) for the qemu process of ...
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2answers
50 views

Can the server administrator browse date of the hosting based KVM Virtualization?

The hosting in https://www.digitalocean.com/ is based KVM Virtualization. If I purchase a their hosting , and upload private data, can the server administrator browse all my of date?
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66 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 ...
0
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1answer
90 views

IPv6 routing under KVM virtualization

I'm having trouble configuring IPv6 routing under KVM virtualization, and I need your help! On the host machine. It uses bridge (named br0) to give its guest machines Internet access. On the guest ...
0
votes
1answer
18 views

Files left over after removing KVM guest

Looking at this post I ran the following commands to remove a VM: sudo rm /var/lib/libvirt/images/centos01.qcow2 sudo virsh undefine centos01 --managed-save --snapshots-metadata But it looks like I ...
4
votes
1answer
229 views

WARNING KVM acceleration not available, using 'qemu'

Running debian (Linux Rick 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1+deb8u6 (2015-11-09) x86_64 GNU/Linux) Looking at my cpuinfo I can see I have vmx support: flags: fpu vme de pse tsc msr pae mce ...
1
vote
1answer
63 views

Can't ping from guest CentOS 7 VM to another guest CentOS 7 VM

I have a problem with ping VM from and to another VM that run CentOS7. The hypervisor is KVM and I control all with CloudStack. The strange thing is that I can ping from and to secondary storage vm ...
0
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1answer
26 views

QEMU/KVM nic properties

1) What's the use of the addr value when specifying a new network interface on QEMU/KVM ? Example: qemu -hda deb.img -net nic,addr=192.168.1.10 2) Is there a way to specify directly the IP address ...
2
votes
1answer
126 views

KVM Virtual Machine: Wrong Disk Size

Ever since I did yum update and tried to create a new (for example) 10GB Disk KVM VPS, the reported disk space inside VM is locked to the initial template size (usually 1GB for linux template). ...
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0answers
20 views

Is there a way to get the KVM Guest using alias interfaces to communicate with one another?

I've done lots of reading and it seems I have misconfigured my KVM Server. I would mess with the networking to get it to work but everytime I have, my company had to send somebody over while I try to ...
3
votes
1answer
32 views

How can I increase vCPUs on VM without powering off in RHEL 7

I am trying to increase vCPUs on a VM. I have done this in the past. Poweroff the VM Configure for maximum allowed vCPUs virsh setvcpus vm-1 10 --maximum --config Change for current settings ...
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0answers
26 views

Qemu - Reduce virtual disk size

I have a problem trying to reduce a virtual machine's disk. The host is CentOS 6.5 and the guest is Windows XP. The size of the virtual drive is 250GB, but I want it smaller. How can I do that? ...
3
votes
1answer
43 views

Activate Intel VT-d in the kernel on CentOS7

Following many tutorials, they ask you to alter the grup file at the /boot/grup/grup.conf.. but in Centos7 there is no /boot/grup/grup.conf ... Activate Intel VT-d in the kernel Activate Intel VT-d ...
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0answers
9 views

create a kvm/qemu vm from vbox config… network adapter configuration?

I have a virtualbox image and configuration file (.vbox) that I want to run under kvm or qemu. I converted the disk image file to a .qcow2 image file, however I'm not sure if there are any tools that ...
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1answer
27 views

TFTP for libvirt hosts behind NAT

This has taken me all day to work out, so I thought I would get this recorded here! I have a LibVirt host with NAT instead of bridging for the hosted virtual machines, using the default IPTables ...