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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111 views

Adding SSD cache (PCIe) to existing Linux KVM Node with SATA disks

I currently have large KVM nodes utilizing between 8 & 16 RAID10 arrays & hardware raid. We typically provision a single large volume (VM's are backed up off site as well). KVM VM's using LVM ...
3
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1answer
1k 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 ...
3
votes
1answer
477 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
219 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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1answer
489 views

vanilla ubuntu-vm-builder on i7 aborts aborts (with PAE?)

host: intel i7-4* cpu, running linux kubuntu 14.04 guest: attempting to create. ubuntu-vm-builder kvm saucy eventually, Get:1 http://archive.ubuntu.com/ubuntu/ saucy-updates/main ...
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1answer
75 views

Is the ethx mac address of a VM the same as the mac address of the corresponding tap interface?

I have a single node openstack install on an ubuntu machine. For some reason that I cannot figure out, the linuxbridge is dropping packets from this VM. My iptables seem to be fine (atleast as far as ...
2
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1answer
472 views

Why is there a socket interface on the host and a character device interface on the guest for virtio-serial?

I am trying to establish a communication channel between the host and one of its guest virtual machine using kvm as a hypervisor. For this, I am using virtio-serial. To create the virtual machine, I ...
2
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1answer
728 views

capping VM IO with cgroups

I'm using cgroups to cap disk IO that a VM does by using libvirt's support for cgroups. So, I'm getting the major/minor number of the device from a 'ls -lL' on the drive where the '.img' file for the ...
2
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1answer
454 views

OpenNebula-managed libvirt not allowing access to /dev/kvm

I have a fresh Open Nebula 3.2.1 installation which I'm trying to get working and manage some freshly-installed debian squeeze kvm hosts. My problem is that when Open Nebula deploys VMs the KVM ...
2
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1answer
929 views

virt-install kept on adding --no-reboot - even though I don't want it to

I have a bit of a problem getting my guests to reboot after the OS installation using virt-install. For whatever reason, virt-install insists on inserting "--no-reboot" when you create a VM: ...
2
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1answer
444 views

Setting up reverse proxy for virtual machines on HostOS

I am currently installing a server that consists of a Virtualization Host (kvm on ubuntu) and 7 VM's, some running MySQL and LDAP, others running different webservers and webapplications. The VMs ...
2
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1answer
606 views

Ubuntu Server mdadm drbd ocfs2 kvm hangs under heavy file reading

I have deployed four ubuntu 10.04 server. They are coupled two by two in a cluster scenario. on both sides we have software raid1 disks, drbd8 and OCFS2 and on top of it some kvm machines run with ...
2
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1answer
505 views

Installing and running a guest OS on KVM-qemu with only serial console access

I am trying to installing a bsd distro with virt-installer. With a Linux distro I used this: virt-install -n debian -r 1024 --vcpus=1 --accelerate -v --disk ...
2
votes
1answer
726 views

Windows NT from vmware to kvm

I'm trying to convert a couple of old Windows NT virtual servers from vmware to KVM. I tried almost all guidelines and how to I found around the web but with no luck. I have the vmware virtual disk: ...
2
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1answer
536 views

Give a KVM Guest only access to OpenVPN

I'm in a kind of weird situation where I need to do the following: Connect an OpenVPN tunnel with static RFC1918 IPs (think of 10.3.3.1 for the server end and 10.3.3.2 for the client end) and have it ...
2
votes
1answer
239 views

KVM QEMU looses USB devices

I have a KVM Qemu setup. I'm mapping a USB device to a VM running windows vista. I get the device mapped, and all is well for some time. Suddenly the device disappears in Vista. If I do "lsusb" in ...
2
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1answer
387 views

iptables string match works on VM host but not guest

Have been tested some iptables string match rules on Linux KVM virtual machines with a bridged interface (Fedora 12 & 13 64-bit), for example a rule in the INPUT Chain that is before other port 80 ...
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1answer
29 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 ...
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1answer
37 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'> ...
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vote
1answer
83 views

CentOS Qemu+KVM lot of virtual machine processes

I am on host-machine with Centos 6.5, qemu+KVM and 2 virtual hosts in it (behind NAT). Both virtual hosts were configured with Virtual Machine Manager (one of them is with Windows 2003 and other with ...
1
vote
1answer
202 views

VPN SSTP windows client can not ping or connect to VPN server but it can talk to every other PC on the local LAN that VPN server is on

So I have an SSTP (with native Windows client) working fine in a sense. My windows client's local IP is 192.168.10.11 , so its local network is: 192.168.10.x The Remote VPN server is behind a router ...
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1answer
265 views

Pass an USB hub from a KVM host to a guest with libvirt

I have the following USB devices on a Linux server: # lsusb -t /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/2p, 480M |__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/6p, 480M ...
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1answer
559 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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1answer
1k views

OpenVPN connects and access to ip works but not url in browser

I have been struggling for 2 days to setup Openvpn access to one of my servers but something doesn't work. First about my setup: My server is Debian 6 installed on vps on kvm environment. I have ...
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1answer
986 views

Linux - KVM - very slow disk io

The I/O performance of my new server is pretty low. I Googled and tried everything I can imagine. First of all, here are the Hardware Components: AMD Opteron(tm) Processor 6344 4x Seagate ...
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1answer
120 views

CentOS 6.5 Server Lockup

Today one of our CentOS 6.5 KVM nodes from OVH crashed after 46 days of uptime and we were unable to find the reason why, we had this issue before with the OVH kernel on another server but this one is ...
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1answer
367 views

Ping (DUP) with Linux bridges and tap devices

http://imgur.com/qPoy2QJ I have two Linux (Ubuntu 12.04) VM (running on KVM) that networked together using two Linux bridges as shown above. The network interfaces are Linux TAP devices. The problem ...
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1answer
180 views

kvm hypervisor kernel panic

My kvm hypervisor had been running with 20+ vps guests for a few months. But a few days ago it went to kernel panic. There were no abnormal operation that I found would cause the problem, except that ...
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1answer
152 views

Bridging is breaking the server: KVM configuration

I'm pretty new to networking and just can't get my head around this. I'm trying to setup KVM-Qemu so I can run some virtual machines. The instructions I'm following are telling me to use eth0 and ...
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1answer
2k views

Assign ipv6 address to KVM guests on bridge mode

System: CentOS 6.5 Network: Bridge on br0 IPv6: ISP Native /64 block. IPv4: ISP address (not internal LAN) Purpose: To assign IPv6 only to guests (manually), I don't want ipv4 address to be ...
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1answer
317 views

kvm guest can not connect to outside of host, vice versa

I have a vmware vm running ubuntu 12.04 server(name=vmhost), with network bridged and full access to the internet. This vmhost is using the kvm hypervisor and is running a vm(centOS 6.4),network ...
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1answer
205 views

virt-viewer slower than virt-manager when viewing

I've got a thin client server in which I have a few VM's for users under KVM which I manage through virt-manager. What I've noticed is if I start a VM guest on a thin client using the command ...
1
vote
1answer
348 views

KVM Slow performance on XP Guest

The system is very slow to do anything, even browse a local folder, and CPU sits at 100% frequently. Guest is XP 32 bit. Host is Scientific Linux 6.2, Libvirt 0.10, Guest XP OS shows ACPI ...
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1answer
405 views

KVM bridge network initial setup - 2 public IPs

I have actually two problems with my server. The setup is like this: server in a data center connected directly to the internet one network card / two public IPs (one IP the server gets over DHCP, ...
1
vote
1answer
222 views

How can I tell what Hyper-V enlightenments a 2008R2 guest is using?

I have a Server 2008R2 guest running inside a KVM host. I've enabled various Hyper-V enlightenments through KVM (-cpu host,hv_relaxed,hv_vapic,hv_spinlocks=0x1000), but I'm not sure how I can confirm ...
1
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1answer
749 views

Proxmox - Assign more memory to KVM VM

Is it possible to assign more memory to a KVM virtual machine without restarting it? I changed the memory size of a VM using the Proxmox web interface, but can't see that increase in the guest.
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70 views

Forward connecting IP address to KVM guests

I'm running kvm with iptables configured to use DNAT and masquerading. However the guest machines are logging the host bridge ip not the connecting client IP address. Is there a way to configure ...
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0answers
1k views

the file-system of kvm virtual machine went to read-only after live migration

I setup my kvm virtualization environment with GlusterFS, the topology as follows: KVM1 ---------- KVM2 --------------KVM3 |----------------------|-------------------------| ...
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2k views

KVM LVM-based guest… kernel: Buffer I/O error on device. Failing drive?

Currently setting up a small KVM host to run a few VMs for a small business. The server has 2 drives in software md RAID 1, then I have it set as a PV in an LVM setup. Guests and hosts are all CentOS ...
0
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0answers
236 views

KVM - 2 external IPs - NAT - forwarding multiple ports to multiple VMs

I have a server with one network device and two external IP addresses. This server is running Debian 7. On this server I want to run two or three virtual machines using kvm/qemu. I want to use both ...
0
votes
0answers
258 views

qcow2 Disk size much bigger than virtual size

What would cause this? ls shows the qcow2 to be 241G, in the VM it only has ~ 160 GB drive, no unpartitioned space. Win 7 VM, Host = EXT4 2.6 Kernel virsh 0.9.10 file format: qcow2 virtual size: ...
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0answers
131 views

LinuxBridge Plugin configuration seems broken in my OpenStack Grizzly set-up, but how to debug it and fix it?

I used theses scripts (OpenStackGeek) to install a Single-node OpenStack Grizzly on an Ubuntu 13.04. Everything seemed to work quite fine until I tried to reach one VM. Unfortunately, no VM was ...
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0answers
170 views

KVM guest network breaks under load

We've been experiencing network problems in our KVM guests for a long time now, and I can't figure out what the problem is. We have multiple servers hosted at Hetzner in germany, these machines are ...
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0answers
65 views

Trying to communicate between virtual servers on the same host through ipv6

I am running KVM on a host with 2 virtual servers. Each virtual server has a own bridge interface on the host VPS1 has br1 VPS2 has br2 Each virtual server has a own ipv4 and a ipv6. The virtual ...
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112 views

KVM directly connect to guests without passing router

I have a KVM host running 5 virtual servers. Each virtual server is using a separate bridge interface, like br0, br1, br3... Each virtual server has a own public IP. Now, I would like to be able to ...
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333 views

kvm guest having temporary network drops

I have a Scientific Linux 6.3 KVM host running 2 nearly identical Ubuntu 11.04 guests. I built 1 base image and then cloned. Each vm has mysql and different RoR app installed on apache, using nginx as ...
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465 views

Routing issue with KVM: Gateway on different Subnet than VM

I have Server at hetzner.de, with a /29 subnet for running KVM-VMs. The VMs get network access via a bridge interface. I'm currently using two IPs from the subnet. The VM-host is running Ubuntu 12.04 ...
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0answers
136 views

how to carp two interfaces on same node?

I have this CentOS machine with 2 interfaces. eth0--> br0 (.10) eth1--> br1 (.11) Although part of the same network, each interface is being fed from a different switch. I use each bridge in ...
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0answers
3k views

Unable to download the Kickstart file…

I have tried for several hours to get this Kickstart installation going but to no avail. I have port 21, 22 and 80 opened and even tried FTP and HTTP to access this Kickstart file but it won't work. ...
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102 views

kvm guest Network interface Authenication failed

i have a kvm host based on ubuntu 10.04 host , and also the guest is ubuntu 10.04 64-bit, guest's network adapter is e1000 on the guest i tried to execute mii-tool eth4 SIOCGMIIREG on eth4 failed: ...