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, ...
7
votes
8answers
1k views
Virtualization: Guest in guest?
Does it make any sense to run a virtual machine with a "master" guest,
and in that master guest run many other guests?
Has anyone tested this? Is it even possible?
Are there better ways to accomplish ...
9
votes
3answers
12k views
Snapshot/rollback for libvirt+KVM?
I've recently begun using KVM for my development/test environment on a Linux host system with 8G memory. Prior, I was using VMware Fusion for my virtual environment, but my Macbook only has 2G memory. ...
3
votes
4answers
5k views
Virtualized CPU cores vs. threads
We've got a KVM host system on Ubuntu 9.10 with a newer Quad-core Xeon CPU with hyperthreading. As detailed on Intel's product page, the processor has 4 cores but 8 threads. /proc/cpuinfo and htop ...
0
votes
2answers
844 views
Migration from Xen to KVM
I have Xen domU virtual machines running Windows. Each of them are installed in their own LVM logical volumes. I want to migrate them to another server with KVM on lvm to.
How can I do this faster ...
-5
votes
1answer
101 views
Consolidating a server and a desktop on one machine [closed]
What is the best way to have a server and a desktop OS on one machine, with the desktop being displayed on a monitor directly connected?
Visualization, with each having a separate guest, seems ideal ...
1
vote
1answer
530 views
Getting windows virtio mounted/installed for KVM
There might be an easy answer to this. I have exhausted my search on google for a solution. Here's my problem.
I need to get Windows working on a KVM vps with virtualizor CP. As I get into windows ...
30
votes
7answers
57k views
Xen vs KVM in performance
What is faster on same hardware - Xen or KVM?
I'm trying to pick-up a virtualization technology to work, which gives the best performance.
There are some benchmarks here that I found on the subject:
...
7
votes
3answers
8k views
Forwarding ports to guests in libvirt / KVM
How can I forward ports on a server running libvirt/KVM to specified ports on VM's, when using NAT?
For example, the host has a public IP of 1.2.3.4. I want to forward port 80 to 10.0.0.1 and port 22 ...
5
votes
2answers
3k views
KVM on Illumos (OpenIndiana vs. SmartOS)
I'm considering virtualizing a number of guests onto a single server running a recent port of KVM to Illumos. It sounds like my two primary options will be OpenIndiana and SmartOS. The distribution ...
4
votes
2answers
5k views
Backup of KVM guests when using qcow2 disk files
I got a Ubuntu (hardy) system used for virtualization using KVM. Each guest got it's own qcow2 file used as disk. Guests are running Ubuntu (hardy). What would a good backup strategy be for such a ...
11
votes
6answers
14k views
KVM Guest installed from console. But how to get to the guest's console?
I'm trying to install a fully virtualized guest (Fedora 14 x86_64) on KVM (RHEL 6), using command-line only (both hypervisor and guest). It goes without errors, and without a tangible result . I'd ...
5
votes
1answer
500 views
KVM/Qemu, Ubuntu: Why do more guests CPUs enhance Disk-I/O rapidly?
We have an Heartbeat/DRBD/Pacemaker/KVM/Qemu/libvirt cluster consisting of two nodes.
Each node runs Ubuntu 12.04 64 Bit with the following packages/versions:
Kernel 3.2.0-32-generic #51-Ubuntu SMP
...
5
votes
3answers
7k views
KVM: Which CPU features make VMs run better?
We are using Ubuntu 12.04 with the following parameters:
Dell R910
Kernel 3.2.0-25-generic #40-Ubuntu SMP x86_64 x86_64 x86_64 GNU/Linux
kvm 1:84+dfsg-0ubuntu16+1.0+noroms+0ubuntu13
qemu-kvm ...
8
votes
3answers
3k views
KVM/qemu - use LVM volumes directly without image file?
I'm not quite sure how to phrase this question (hence the poor title), so let me provide an example of what I'm trying to do.
On my (old) Xen host, I'm able to present LVM filesystems directly to ...
7
votes
3answers
4k views
LVM volume group shared between KVM/libvirt host and guests: is this a bad idea?
I have just built a shiny new KVM/libvirt-based virtual machine host, containing 4 SATA II hard drives, and running CentOS 5.5 x86_64.
I have decided to create virtual machine disks as logical ...
4
votes
3answers
2k views
Is KVM stable enough for production use in 2011?
We are planning to virtualize the existing infrastructure by an open source virtualization solution. KVM and Xen are on the final list. Big cloud players are still using Xen, and we found that KVM is ...
3
votes
1answer
298 views
Why does host swap out VMs when there are 16GB of buffer cache and swappiness = 0? [duplicate]
I have a desktop running Ubuntu Quantal using OpenStack Folsom on an Intel i5 with 32 GB RAM and 2 GB swap. I'm running 7 VMs each sized like a EC2 m1.small, so 1.7 GB RAM each. I'm using KVM.
As I ...
3
votes
2answers
892 views
Network freezes with KVM/libvirt and ip_forward = 1
I'm using KVM and libvirt and experience small network freezes on the host and the guests every 2-3 minutes or so. The freezes last 1-2 seconds. The used OS is Ubuntu 10 LTS server edition.
I'm ...
2
votes
2answers
2k views
KVM on RHEL 6.1 makes host sluggish
I have been running RHEL 5.7 on a host just fine with several VMs (KVM). No major issues. Time came to upgrade to RHEL 6.1 as a few bugs had been fixed in this release.
When I start a VM or two under ...
2
votes
1answer
2k views
KVM network bridge with public static IP for both host and guests
I have a Ubuntu 10.04 server with 2 public static addresses. There is a KVM guest (also Ubuntu) installed and running. What i want is to give the guest an IP of the host, so that both machines have ...
2
votes
2answers
1k views
Mount LVM within a disk image
I have a disk image that I made with KVM. The partition layout inside the disk image is as follows.
[root@centreon01 2tb-external]# fdisk -lu vdisk1.img
Device Boot Start End ...
1
vote
1answer
839 views
Adding Virtio block devices at runtime in Libvirt KVM
I'm running Debian Wheezy Beta 4 with KVM based guest systems which run the same operating system. I'm using LibVirt to manage the virtualisation.
What I would like to do is to attach an LVM based ...
1
vote
2answers
13k views
pfSense Site-toSite VPN with OpenVPN connects but won't route traffic
Using two pfSense routers, I've created a shared-key VPN between 2 sites. Both routers are pfSense 1.2.2. The pfSense box at the client site is the gateway router for that site, but at the server ...
7
votes
4answers
3k views
Port Forwarding from Host to Guest with libvirt 0.8.3 Using KVM on Ubuntu
The host has a single external IP available, so I set my KVM guests up with NAT.
How do I set up a port forwarding to forward some of the requests from the outside to the guests?
I couldn't find ...
5
votes
2answers
2k views
use LXC under heavier virtualization (Xen, KVM,Hyper-V,VMVare)
Is it possible to use LXC under heavier virtualization (Xen DomU,KVM,Hyper-V,VMVare) ? I would like to use it as security (isolation) tool, the ability to limit resource consumption is not priority ...
4
votes
1answer
424 views
KVM virtual machines cannot reach IPv6 web sites
I have a freshly installed Windows Server 2008 R2 SP1 virtual machine which is completely unable to reach any IPv6 web pages, despite apparently having proper IPv6 connectivity. In addition, other ...
3
votes
2answers
1k views
Debian: Should I add vlan interface into bridge for KVM?
I am setting up a Debian Squeeze box as a KVM host. I want to add multiple interfaces to each KVM guest so I want them to be on different VLANs.
After reading about this, I believe the best method is ...
3
votes
3answers
722 views
KVM “live migration finished” detection
I'm using KVM (through libvirt actually) for a research project. We're live-migrating a virtual machine between different subnets, so after the migration the IP address and routing tables have to be ...
2
votes
2answers
2k views
KVM and virtual to physical CPU mapping
I'm a relative late comer to the virtualistion party, so you'll have to forgive me if this seems like an obvious question.
If I have a server with 12 cores available, does each KVM guest have access ...
2
votes
2answers
5k views
How to install virtIO drivers for Win 2008 on KVM?
This is a follow up to a pervious question. I have a Ubuntu host with a Win 2008 KVM. To improve performance the network and IO - @dyasny and the documentation recommends installing virtIO drivers. I ...
1
vote
0answers
97 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 ...
1
vote
1answer
426 views
Poor guest I/O performance KVM Ubuntu 12.04
I have a guest VM running inside a 12.04 Ubuntu host. VM was created using the vmbuilder python script.
On the host the phoronix-test-suite "aio-stress" gives a performance speed of >1600MB/s Random ...
1
vote
1answer
540 views
Linux-KVM / iptables: prevent guest spoofing by matching ip+mac address on bridge?
I have my KVM guests on a standard br0 bridge setup:
auto br0
iface br0 inet static
address 192.168.1.117
netmask 255.255.255.0
network 192.168.1.1
broadcast 192.168.1.225
gateway ...
1
vote
3answers
1k views
sysctl.conf not running on boot
At what point is sysctl.conf supposed to be read during boot, and why might it not be running? I have the following settings which are not being applied when I reboot:
...
1
vote
3answers
2k 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
3answers
1k views
KVM booting off-image kernel and existing partition
I am in the process of switching from Xen to qemu-kvm. My current Xen installation has a number of LVM volumes each with a partition (rather than a full disk image). In Xen, I start each VM with a ...
3
votes
1answer
572 views
High I/O latency with software RAID, LUKS encrypted and LVM partitioned KVM setup
I found out a performance problems with a Mumble server, which I described in a previous question are caused by an I/O latency problem of unknown origin. As I have no idea what is causing this and how ...
3
votes
1answer
202 views
How can I run Startup Repair on a KVM virtualized Windows Server?
I have Windows Server 2008 R2 running virtualized in a KVM virtual machine.
Recently the virtual machine decided to stop booting, and it offered to Launch Startup Repair. However, upon entering ...
3
votes
5answers
6k views
KVM online disk resize?
We're evaluting KVM for Linux virtualization on a few projects. All is going well so far. But one of our requirements is the ability to add disk space to a running guest without rebooting or taking it ...
3
votes
1answer
7k views
How to copy KVM disk image to LVM
Problem
I'm getting a No space left on device error when doing a dd command. I'm trying to move a KVM qcow2 file to an LVM partition and thought that the LVM partition needed to be the same size as ...
2
votes
2answers
376 views
Multiple IP addresses assigned to one KVM VM
System:
OS: Debian 6.0 64-bit with KVM installed from packages
KVM is managed with Cloudmin 6.4.kvm
I have a /29 subnet from my host. The bridge is setup properly for each VM to have its own IP, ...
1
vote
1answer
215 views
KVM guest time shift on host reboot
I have installed Ubuntu server 12.04 as a KVM host, and created an Ubuntu guest that is also running Ubuntu server 12.04. The servers are in the AST time zone which is UTC + 3 hours. After setting the ...
1
vote
1answer
202 views
Bad Mumble control channel performance in KVM guest
I'm running a Mumble server (Murmur) on a Debian Wheezy Beta 4 (x86_64) KVM guest which runs on a Debian Wheezy Beta 4 (x86_64) KVM hypervisor. The guest machines are attached to a bridge device on ...
1
vote
1answer
330 views
Can KVM CPU assignment count differ from physical hosts CPU count?
I have read this question. I knew already that I could for example, have a quad core machine with four guests each having two vCPUs. As they don't all be require 100% CPU usage all the time, the ...
1
vote
6answers
789 views
Will the OS crash if the system partition can't be access for a short period?
An operating system is installed in a virtual machine environment, such as VMWare or KVM. A network shared disk volume (e.g., iSCSI disk) is used as the OS system partition. Heavy traffic is running ...
1
vote
1answer
974 views
Connecting to a KVM guest OS in Ubuntu
I am lost on this. Basically I am trying to set up a Ubuntu Server 10.10 as a virtual machine by using KVM. Everything went smoothly and I can even sudo-apt get packages from the guest OS.
Now, ...
0
votes
1answer
82 views
KVM guest has a wrong outgoing ip address
I have a KVM host with a bridge configured on eth0 that has a public ip:
auto br0
iface br0 inet static
address xx.xx.aa.111
netmask 255.255.255.0
network xx.xx.aa.0
broadcast xx.xx.aa.255
...
0
votes
1answer
694 views
Use one NIC to create multiple interfaces for Linux KVM
I am working on a thesis research project, and I am having some difficulty figuring out how to make one NIC spawn several "bridge" interfaces such that each KVM VM can be seen on the local network. I ...
0
votes
2answers
867 views
KVM with one host IP and a different subnet for machines
I've already setup a KVM host with proper IP configurations, but my host had me create DHCP and use that to assign the IP's to the machines. I want to see if there's an easier way to do it (or ...
0
votes
1answer
621 views
Debian Squeeze guest running under KVM, how to get serial?
I've just got it running on Ubuntu, have installed everything but the kitchen sink.
Got virt-console, virt-manager, running debian Squeeze, everything works.
But... I don't want to connect via vnc. ...
