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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826 views

Very poor disk performance on KVM node - mdadm raid10

For a long period of time, i'm experiencing performance issues on CentOS servers that are used for KVM virtualization. I'm running software RAID-10 with 4 disks (Seagate ST2000DM001, 2TB, 7200rpm ...
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47 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 ...
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55 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 ...
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0answers
57 views

How to relate cloudstack volume ID to guest virtual block device ID?

Under CloudStack 4.2.1, I have an Ubuntu 14.04 guest with 3 attached volumes of the same size. From the CloudStack management page, I can see that each attached volume has a name and an ID (and a ...
2
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308 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 ...
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213 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 ...
2
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602 views

virtualbox to qemu but results in no bootable device qemu

I use vagrant to create my development vm. I exported the vmdk to vdi, and then convert the vdi to img. cd virtualbox_dir/test_vm VBoxManage clonehd test_vm.vmdk raw.vdi 0% ..... 100% qemu-img ...
2
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410 views

preseed command string fail with newline character using virt-install initrd-inject

I am creating a new virtual machine using libvirt's virt-install command. The command pulls a local preseed file from the hypervisor using initrd-inject: virt-install \ --autostart \ --name vm1 \ ...
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234 views

Slow Transfer Speeds from KVM host to client

I am trying to isolate the root cause of slow transfer speeds from my host OS to a KVM client. Both are Ubuntu 12.04 LTS Linux. Rsync on the host 192.168.1.72 rsync -auv --progress rut3.img /tmp/ ...
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209 views

KVM on Ubuntu: Port forwarding to a guest VM

I installed kvm and set several guests on a server using vmbuilder. Here is the following configuration : server host1 (xxx.xxx.xxx.xxx) -> guest vm1 (192.168.0.3) ...
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372 views

KVM host kernel configuration for best performance

I'm currently building a kernel for my server, which should serve for hosting virtual machines using KVM. There are a few kernel configuration options that are already described in the KVM-Wiki. The ...
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290 views

What is the preferred clocksource for a kvm guest running debian?

Our development server is running debian 4.0 (etch) as a guest under KVM. For the longest time, it had sporadic issues where many processes would appear to just hang. We finally found the issue - the ...
2
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598 views

KVM Guests & IPv6, Connectivity breaks after some time

Goal: Assign public available IPv6 adress to every guest Problem: Working IPv6 connectivity suddenly stops working. After starting everything up (network on host, guests) everything works fine. i can ...
2
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0answers
299 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 ...
2
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0answers
113 views

Windows 2k3 server as a KVM client

Just wondering if anyone else has had issues installing Windows 2K3 server under KVM. I have tried a few times tonight and keep getting "not a supported platform" when the installation first boots. ...
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0answers
10 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 ...
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14 views

Why privacy ipv6 address cannot connect the internet in guest vm

I have a guest ubuntu 14.04 installed in kvm, host is a fedora 20. The eth1 nic of guest is in macvtap bridge mode. Ubuntu default enables ipv6 privacy extension, and prefers the temporary address: $ ...
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34 views

KVM: VNC connection blocked

I'm running a KVM host with three client vms. Two ubuntu servers and one windows server r2 2008. All three VMs have the VNC option enabled in their XML config file: <graphics type='vnc' ...
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52 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 ...
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0answers
60 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) ...
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0answers
162 views

Weird Phusion+nginx spawning delay error

We are trying to migrate an application written on REE from cloud provider A to cloud provider B. The application code, VM specs and operating systems are the same. The basic difference is that cloud ...
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44 views

Virtuall Manager : CentOS Guest Install Garbled Text

I'm trying to install CentOS 6.5 with virtual manager but the menu is garbled. Host machine is running on Debian Wheezy. Thank you in advance.
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90 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 ...
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814 views

Ubuntu 14.04 KVM Host - Only network device pcnet working

I've installed a KVM host on Ubuntu 14.04. I've added a networking bridge as br0 and also added the p4p1 network adapter to it. My problem is now that only the "pcnet" networking guest driver is ...
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60 views

CloudStack virtual machines slow down over the course of a day

I run CloudStack 4.3 using KVM on an Intel(R) Xeon(R) CPU E5-2620 on Ubuntu 14.04 LTS. When I first start a virtual machine it runs quickly. Over the course of the day it slows down to acceptable. ...
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105 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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62 views

Change sender-IP for VM in libvirt behind NAT

I have a server with my own public /28 IPv4 Network. On this server I have some vServers, done with KVM/libvirt. These vServers are connected with a virtual network, NATed to the internet. Every ...
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160 views

Slower VM Performance for Headless Browser Tests on Xeon

I created a virtual machine on my desktop to run our continuous integration process. After I was happy with it, I moved the VM (keeping the same configuration) onto our server where I found that the ...
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0answers
64 views

virsh vcpu_period and vcpu_quota

I have been looking into ways to divide my CPU amongst KVM guests other than by just setting vCPU access limits. I understand the concept of cpu_shares which can be set/displayed with virsh schedinfo, ...
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0answers
81 views

Asus ASMB4 KVM - How to restart from bash command line?

I have a remote server that hasnt been access in a while and it seems the KVM web interface is not working. I can SSH in and get a prompt but I dont have any idea how to either: -reboot the KVM only ...
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0answers
97 views

How does virt-install create and persist and secure the boot disk?

Normally when i run virt install, I boot initially from the network, by installing from source, and also including a "--disk" option. The way i do it is described here ( in the "root" of this ...
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394 views

Migrate CentOS VM using LVM on IDE to run with VirtIO

I'm trying to migrate existing IDE-using, LVM-based CentOS 5.2 VMs to use virtio. The symptom is a kernel panic upon boot when the system can't find any volume groups. Does anyone know how to make ...
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0answers
71 views

__ticket_spinlock high cpu

We are having a strange problem on our Ubuntu 10.04 KVM infrastructure, where periodically, one of two vm webservers freaks out, with persistently high load, even if we restart the applications. (the ...
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0answers
194 views

SSD+MDRAID+LVM+KVM results in lower performance than expected

We use kvm for virtualization, the disk images are stored as logical volumes. The logical volumes are stored on a bunch of software-RAID1 (mdadm) arrays composed of Intel DCS3500 SSDs (each array is a ...
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0answers
71 views

Bridging Adapter in Ubuntu 12.04 LTS for KVM

Fresh install of Ubuntu 12.04 LTS with libvert/KVM installed. I have 2 virtual machines that I need need to be on the same LAN as the host. The host has two physical interfaces eth0 and eth1. eth1 is ...
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0answers
99 views

VDA Disk Fail / Virtual machine corrupt

I am hoping I can get some help here. I have a server that is hosted with a very large server hosting company and today the server became unavailable. On contacting the company they said that the ...
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0answers
654 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 ...
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0answers
484 views

Ubuntu server 13.10: Installing and running Archipel from deb packages

I am setting up a server to host virtual machines based on Ubuntu Saucy. The decision was to use Archipel for remote administration. Installation of ejabber and Web Client UI went smoothly. For the ...
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0answers
300 views

Routing suddenly broke on a KVM guest

I have a CentOS-based host and a KVM Debian-based virtual machine on it. A host has an Ethernet bridge on its external network interface, this bridge is used by KVM: br0 Link encap:Ethernet ...
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0answers
211 views

Volume unreadable in KVM guest after host volume resize

I have a KVM guest requiring more space on one of it's partitions. This partition is actually an LVM volume on the host. So I first unmounted the partition in the guest, switched to the host and ...
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0answers
302 views

nwfilter: Generated firewall rules don't make any sense

I'm trying to configure nwfilter for KVM, but so far I haven't managed to figure out a working configuration. Network setup: The dom0 (Debian 7.1, kernel 3.2.46-1, libvirt 0.9.12) is connected via ...
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0answers
268 views

Windows Server 2012 on KVM behaving as if Windows Key is getting hit repeatedly

I've got a brand new install of Windows Server 2012 Essentials running on KVM on OpenSuse 12.2. When I VNC in to the VM (using the VNC server provided by KVM, not one installed on the guest OS), it ...
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0answers
92 views

KVM .img can not boot after resized by virt-resize

I have a CentOS 6.4 image install by KVM on Ubuntu 12.04 amd64 host. Here is the disk layout of centos.img # virt-filesystems --long -h --all -a centos.img Name Type VFS ...
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0answers
212 views

Assign IPv6 addresses to kvm virtual machines using DHCP

I created a bridge using brctl called dhcp_test_br, and bind my new created kvm virtual machine to this bridge. Then I ran dnsmasq: dnsmasq --strict-order --bind-interfaces --interface=dhcp_test_br ...
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518 views

debian KVM - network bonding fails with vlan and bridge

i have a Debian 6 system configured with 2 NICs these NICs are used on a bond (bond0) which is used by bridge that require to use VLAN. i can get connection between guests running on VLAN10 but it ...
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0answers
436 views

Ghost “vlan 0” tags added to ethernet frames in CentOS guest under OpenStack

I'm trying to debug an issue involving a KVM virtual machine instance where the instance doesn't respond to network requests when the source is on another physical machine, which is on the same subnet ...
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0answers
517 views

How to import XenServer's ovf/ova/xva format to KVM?

Now I'm considering migrate from Xen to KVM. I exported some exist virtual machines from Xen in the formats ovf and xva. How could I import them into KVM? As there're only a few of virtual machines, ...
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0answers
627 views

“sched: RT throttling activated” KVM host - what does this mean?

Ubuntu 12.04 64bit - under a KVM parent. 32 cores. So we seem to be having some load issues. We have noticed this line in kern.log: "kernel: sched: RT throttling activated" What does this mean? Is the ...
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0answers
316 views

qemu/kvm: connect two machines via ttyS0

I would like to connect two machines via ttyS0 Here's what I did on the guest machines: A: Add to /etc/inittab: S0:2345:respawn:/sbin/mingetty ttyS0 Add to /etc/securetty: ttyS0 B: Try to ...
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0answers
335 views

KVM USB Passthrough and Zydas usb wireless adapter: device or resource busy

i'm tring to setup a kernel testing virtualmachine for a 80211 module. i start my machine with this command: kvm -m 512 -net nic -net vde -usb -usbdevice host:0ace:1215 ktesting.img i set up a ...