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-...

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KVM virt-clone while the VM is running

Is it possible to clone a running kvm machine without tools like virt-clone? They already have the original vm in production, I cannot shut it down. If I don't care about temporary data corruption (...
2
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2answers
1k views

upstart pre-stop script

I have libvirt/KVM set up on my Ubuntu and before shutting down the machine I would like it to attempt shutting down the VM's using an ACPI poweroff (virsh shutdown), then I want it to stop shutdown ...
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0answers
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KVM - Lost connection with virtual machines

I have to change de ip address of hypervisor KVM and his virtual machines, but when I restart de network services in physical machine, I lost the connection with the virtual machines. I’m using suse ...
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1answer
30 views

Possible DDoS (not sure). Cannot trace with netstat

I have a KVM node I'm running with only 7 VM instances. When GigE uplink port is enabled, server connection goes crazy hitting over 300MBps somehow. I cannot trace which IP is possibly being attacked, ...
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3answers
57 views

Multiseat Linux Remote Desktop with KVM and Spice

I have a server running Ubuntu 14.04LTS. On it I created a (KVM) VM with Ubuntu 16.04 Desktop. I setup Spice on this VM so that I can access it remotely. Everything is working fine, got TLS, USB ...
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2answers
727 views

How do I extend the virsh/qemu/libvirt Timeout?

There's a known issue with starting virtual machines with large hard drive images. Apparently, the time-out is 3 seconds, but in reality, it can take up to 15 seconds for a machine to start. I've read ...
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2answers
1k views

internal error: unable to execute QEMU command 'cont': Resetting the Virtual Machine is required

I try to install a kvm img in my vps, but after i install it, it show root@wz:~# virsh list Id Name State ---------------------------------------------------- 12 ...
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1answer
2k views

Error while creating VM using virt-manager on Xen

After a great struggle I got my XEN installed now I am using virt-manager and trying to create a VM. Since my H/W doesnt support full Virtualization using the Para Virtualization installation over ...
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0answers
6 views

kvm “could not read from cdrom (code 3)” [on hold]

The VM "ran" (didn't fail to start due to an error) but immediately stopped with boot failure (no boot device). When I finally found the answer to this I thought it was worth posting for others ...
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2 views

Could RSync be used to backup Parallels vm to KVM? [migrated]

So I am currently using Parallels on my macbook pro but I am wanting to also use them on my desktop, which uses KVM. Since I don't believe KVM can read the parallels file format, would it be possible ...
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0answers
32 views

libvirt IPv6 Guest can't connect outside of the Host

i am trying to get a address from my IPv6-Subnet working in a Virtual Machine(libvirt, qemu). IPv4 over nat works like a charm. The host is a Debian 8.5 with qemu 1.2.9 and a 4.6.3-1~bpo8+1 (2016-07-...
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7answers
3k views

recommendations for efficient offsite remote backup solution of vm's

I am looking for recommendations for backing up my current 6 vm's(and soon to grow to up to 20). Currently I am running a two node proxmox cluster(which is a debian base using kvm for virtualization ...
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2answers
1k views

Get link speed of an virtio-net network adapter

I have an linux vm running on kvm with virtio-net, and I want to check the link speed. How can I do that? What I tried so far: # ethtool eth0 Settings for eth0: Link detected: yes It seems that ...
2
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3answers
111 views

KVM-Host lost connection to Storage

I would really appreciate some advice on how to fix this. I have a Debian KVM-Host with 9 Debian VMS running on it. The virtual machines are running on my little Storage via iSCSI. Now, my switch ...
3
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1answer
2k views

How to make sysctl network bridge settings persist after a reboot?

I am setting up a notebook for software demo purpose. The machine has 8GB RAM, a Core i7 Intel CPU, a 128GB SSD, and runs Ubuntu 12.04 LTS 64bit. The notebook is used as a KVM host and runs a few KVM ...
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0answers
14 views

Restrict internet access with firewall rules for a VM running on Linux [closed]

I have Red Hat 7 running on my workstation, and Windows 10, used for working with Windows programs, in a virtual machine running on KVM/QEMU. The workstation, fulfilling the role as hypervisor, and ...
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1answer
1k 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.
3
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1answer
30 views

KVM direct disk access vs raw files

I have to setup 14TB of raid storage space (which just shows up as /dev/sdb). My question is: Is there any impact on performance from a kvm guest if I create ext4 on this large drive directly, mount ...
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0answers
26 views

xen to kvm migration using virt-v2v

I am seeing error connecting when I try to connect for conversion of xen-vm to kvm. I am use virt-manager w/o problems. Errors seen: [root@localhost ~]# virt-v2v -v -x -ic "xen+ssh://10.61.0.47" "...
2
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2answers
48 views

Linux bonding (balance-tlb), KVM guests and L2 switches = unicast flooding?

I have a unicast flooding problem on my network, that started when I moved some software to virtualized guests. It seems very similar to what reported here: Switch flooding when bonding interfaces in ...
5
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3answers
5k views

set tap0 using virt-manager for bridged wireless

After 3 days I finally have kvm guests working on the network via wireless (link below - thanks!): My network is 192.168.1.0/24 on the host: sudo sh -c "echo 1 > /proc/sys/net/ipv4/ip_forward" ...
1
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1answer
27 views

KVM - Adding public IP over bridge

I am working on setting up a KVM environment and normally I just take it for granted that the networking has been set up. I am running into difficulty getting the public IPs accessible from the VMs. ...
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1answer
2k views

apt-get update can not connect

i run a dedicated ubuntu 10.04 server. i use kvm/libvirt/virsh to run a virtual machine that's also ubuntu 10.04. i bridged the network (1 of 2 IPs is routed via NAT to the LAN, where my VM (192....
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0answers
33 views

Linux ext4 timeout in KVM guest

Both the host OS and the guest OS are Debian 8 amd64. The guest is a raw disk image stored at /srv/machines/web.img. The host has a backup script scheduled each night at 1:55am. Here is my backup ...
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2answers
1k views

How to mount disk on centos 6.4 KVM server

I have Centos 6.4 on KVM server already up running with couple of sites, now i am almost run out with space so i decide buy from the server provider more gb in order to increase the HDD. I contact the ...
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1answer
41 views

Advice needed about RAID and partitioning new server

first of all i want to appolagize if i doublepost. Plese merge this with similar post. Thank you. Now about the situation and the system we are trying to build and want an advice from experienced ...
0
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1answer
76 views

Proxmox-Server reboots sporadically

I just mentioned that my proxmox-system is rebooting from time to time when performing backup-tasks (bacula, not the proxmox-backup-system). The logs are showing the following: Mar 8 02:30:01 ...
2
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1answer
32 views

Auto clean unused space on disks in VM

I run KVM based virtualization server (namely, Proxmox) where some Debian based machines are run in KVM VM's. Proxmox can create backups of VMs, it also compress the VM disks images. As we understand,...
16
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4answers
15k 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 ...
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0answers
18 views

Run same virtual machine twice simultaneously from the same base snapshot

I would like to have a base snapshot and then launch several virtual machines from it simultaneously. These machines have a short lifetime and then shutdown, there is no need to save the changed to ...
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1answer
48 views

Virtualized windows 7 under qemu/kvm hangs

I have set up a windows 7 virtual machine using Red Hat 7's standard qemu/kvm. When I start up the vm, windows boots to the point where it says "Starting Windows" and displays the stylized window. ...
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1answer
2k views

Debian Jessie Qemu KVM GPU Passthrough to Windows Virtual Machine guest Virt-Manager error Bus PCI not found

I'm having problems with Virt-Manager not wanting to boot a VM and giving error: Error starting domain: internal error: process exited while connecting to monitor: char device redirected to /dev/pts/...
2
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1answer
2k 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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0answers
42 views

IRQ changes when trying to virtualize with PCI Passthrough KVM.

While trying to test PCI passthorugh in a KVM machine... I have an odd behavior. I made sure the PCI bridge and device are on an IRQ alone. The card is a Digium TDM400P. LSPCI: -[0000:00]-+-00.0 ...
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0answers
61 views

How to assign ipv6 to my kvm guests route mode

Do you know how assign ipv6 global addresses to my KVM Guests?My ISP provider advertise an ipv6 prefix /64.I use libvirtd an here is configuration. When i restart virbr0 cant communicate with local ...
0
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1answer
44 views

SCSI virtual disks not showing up on RHEL 7.X KVM guests

For whatever reason I can't get my virtual disks to show up on any of my RHEL 7.X guests (libvirt + KVM). The XML is configured just like my other guests so I know it isn't an issue on that end. It ...
8
votes
2answers
16k views

Changing boot device for a QEMU-KVM virtual machine

I am trying to change the boot device for a VM. I go to the VM's XML file in /etc/libvirt/qemu and set <boot dev='cdrom' />. Still, it attempts to boot from the harddrive instead of the cdrom. ...
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vote
3answers
2k views

Exporting libvirt+KVM virtual machines to files

I am going to retire an old libvirt + KVM server, but I need to preserve the VMs. Unfortunately, the network is down and I cannot create connections to the system. Is there any way to export the VMs ...
0
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2answers
2k views

Guest networking not working on Debian Jessie Host server KVM with br0 bridged network

GUESTS networking not working at all. In other words guest can not ping host or lan gateway. I have br0 bridge already created, also brctl show that vnet0 was properly added by KVM to br0 on guest ...
0
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0answers
22 views

Same mac addresses discovered in VM for bridges on host machine

I have two bridges on host machine, named br0 and br1 (having different mac addresses). A VM is connected by bridged networking through br0. Now VM is able to ping br0, which is normal. But it is also ...
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1answer
51 views

The cpu L1/L2/L3 cache see in kvm guest is really matter?

[root@centos7 opt]# cat /etc/redhat-release CentOS Linux release 7.2.1511 (Core) [root@centos7 opt]# lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: ...
1
vote
1answer
955 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, ...
51
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8answers
96k views

How do you increase a KVM guest's disk space?

I setup an Ubuntu guest on a CentOS KVM host with initially 6GB of disk space. How do I go about increasing the Ubuntu guest's disk space from the command line? EDIT #1: I'm using a disk image file (...
0
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0answers
14 views

libvirt vhba storage pool configuration

I'm running a project where I will use libvirt NPIV/vhba functionality to pass Fc LUN's from a SAN to KVM virtual machines. I'm using CentOS7 as host. I will also mostly use CentOS7 as guests. I got ...
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0answers
26 views

OpenStack instances power off by itself

Already asked this over on ask.openstack.org but I figured it would get more views here too. I am running OpenStack Mitaka on a 5 node cluster, 1 controller/network node and 4 compute nodes. I am ...
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0answers
55 views

Is it possible to clone a snapshot of a KVM vm?

I only find an option to clone the last state, but not the state of a snapshot. Is there a solution? I'm using virsh and virt-manager to manage the vm's. The Hypervisor is Ubuntu Server 16.04. The vm'...
0
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1answer
19 views

mount a kvm qcow2 file

so i have a kvm image that i'm trying to mount: [0c79dafb-abb7-4714-9a0a-4e16f0b305e7]# tree . ├── console.log ├── disk ├── disk.info └── libvirt.xml [0c79dafb-abb7-4714-9a0a-4e16f0b305e7]# qemu-img ...
0
votes
1answer
42 views

VM performance difference after moving to different ProxMox instance

I've got two ProxMox servers and when I moved one of my VMs, it's running into performance issues. ProxMox 3.4 running on Intel Xeon E5606 (2 CPUs, 4 cores each, @2.13 GHz). ProxMox 4.1 running on ...
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0answers
45 views

qemu-kvm VM hangs at iowait with virtio drive

We are seeing instances of a VM hanging with the following symptoms: load average 800, processes stuck, CPU 100% in iowait reading files work, writing files hang the system RAM utilization is high, ...
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0answers
30 views

KVM/libvirt: NAT forwarding virtual bridge to host bridge

I currently have a VM setup where only a few 'special' VMs are allowed to have outward facing IP addresses and the rest aren't. All of them are configured with two interfaces attached to a virtual ...