QEMU stands for "Quick EMUlator" and is a processor emulator that relies on dynamic binary translation to achieve a reasonable speed while being easy to port to new host CPU architectures.

learn more… | top users | synonyms

2
votes
1answer
2k views

qemu-system-x86_64w.exe : could not open disk image D:\img.img: Permission denied

I'm trying to use qemu on Windows (8), because I have to emulate an USB mass storage device (VirtualBox still doesn't handle USB3 which my computer only have .. and if I could have qemu working it ...
0
votes
1answer
140 views

qEmu doesn't save changes to virtual harddisk

I've installed qemu and AQEMU on my Ubuntu 13.04 from default repository. I created a virtual machine by using the wizard and set the harddisk to 10 GiB. I added a Debian 7.1 .iso file to the device ...
3
votes
1answer
387 views

KVM: Run a script when a guest is shutdown from within?

I am running KVM as virtualization engine. Is there a way to make QEMU/libvirt run a script on the host when a guest is shutdown from within (shutdown -h now)? I want to be able to run some custom ...
2
votes
1answer
534 views

Signaling KVM/QEMU VM to quiesce, preparing for live backup

Assume a KVM/QEMU VM, which uses qcow/qcow2 as the image format for virtual disks. Backup is (to be) done on the VM host. As far as my current understanding goes is that while we can create backups ...
-1
votes
1answer
266 views

Kvm poor cpu performance

I have running some Minecraft Servers in a Qemu VM over Libvirt, and the performance is only half good than on real hardware. Libvirt started the vm over: /usr/bin/kvm -S -M pc-1.1 -cpu ...
4
votes
2answers
875 views

Issue with creating an Windows 2008 Virtualized image with qEmu

I'm trying to create a qemu image of a 64bit Windows 2008 Server install. It will be used on Openstack as an instance. The Virtualization environment [of qemu] is being run from a VMware virtual ...
3
votes
3answers
2k views

How to efficiently share host's folder with KVM guests?

I am configuring the service which stores plenty of files uploaded by nginx in /srv/storage dir on host system. These files are processed by worker KVM guests which may create new files or assign ...
2
votes
2answers
745 views

How safe is it to access qemu/kvm raw or qcow2 disk image files from host

I've read mixed opinions about how safe it is to modify qemu disk image files. There are two distinct situations I'm interested in. 1) let's take a raw or qcow2 disk image file not used by kvm (i.e. ...
0
votes
1answer
47 views

Using a virtual disk image on two virtual servers

I have a setup with some test and stagiging servers running on the same host (using virsh to maintain it on ubuntu 10.04) The test and staging systems are build up with the same sets of servers. One ...
1
vote
2answers
375 views

qemu-kvm fail to boot Centos 5.3 after Kernel update at the host (feodra)

After updating Fedora 18 to kernel 3.9.x (current 3.9.4), I can no longer boot my Centos 5 guest OS. When I try to boot, the process halt at start and the CPU core work at 100%. If I boot Fedroa ...
1
vote
3answers
1k views

Standalone KVM server best practices

I'm looking at ordering a powerful server machine to use for virtualization. I'm planning on running debian with KVM+QEMU for the virtualization, and a hardware RAID6 to store the VMs on. I would also ...
1
vote
1answer
190 views

Is it possible to create an equivalent environment of a KVM guest using QEMU for Windows?

I have a KVM guest in a datacenter that is my production server for a service I am developing. I would like to create an equivalent virtual environment on my Windows machine so I can be sure that ...
0
votes
1answer
111 views

KVM copy contents of image into raw smaller LVM2 partition

I have a KVM guest, running on a KVM host...both Gentoo Linux. The guest is called webserver.img. It is 21 gigs large, but I am only using 5 gigs inside the image. I want to make a logical volume ...
0
votes
1answer
109 views

KVM how to determine which virtual disk files are in use by VMs

I tried lsof|grep *.qcow2 and got no results back (why is that? I definitely have VMs running using that disk format). I also considered grepping qcow2 on *.xml within the config directory, but this ...
0
votes
1answer
89 views

Can I boot a CD-ROM on a QEMU guest with a hard drive?

If I insert a CD-ROM into my server's physical CD-ROM drive, can I boot that CD-ROM in a QEMU guest to work on that guest's hard drive? I need to use a Windows 7 repair disk. This is a continuation ...
0
votes
1answer
130 views

How to setup qemu as a server with different subdomain on a host server? [closed]

I am trying to solve a problem, with a Linux server work as host, while qemu guest will have another server intended for subdomain. I tried to make the host to access the guest server. And I read ...
1
vote
1answer
98 views

aligning partition boundaries of already installed system

I have qemu raw disk which includes two partitions. The second partition is not aligned according to ssd principles. I will move this into Smartcloud environment and they suggest aligning according to ...
0
votes
2answers
4k views

How do I create an ISO image of a partition on an external hard drive?

I see that there is a similar question with the answer to use BartPE with a plugin, but are there any other methods to create an ISO image from an external hard drive partition? I don't feel too good ...
1
vote
0answers
4k views

VNC faster than Spice for remote access to KVM guest?

Having used RDP before, I'm not exactly thrilled with the performance I am seeing from VNC to my KVM virtual machines. The KVM host is Ubuntu 12.04 server x64. I've read that Spice is faster, and ...
0
votes
1answer
180 views

how do I add a vcpu to one of my KVMs in QEMU?

I want to add a vcpu to a virtual server in QEMU. I tried editing the XML file in /etc/libvirt/qemu and starting the server, but that does not seem to work.
0
votes
2answers
768 views

how do I backup my qemu kvm img files that are block files?

I inherited a pair/cluster of Ubuntu 10.04 servers running DRBD and QEMU/KVM and I want to backup the img files but they appear to be block files on the DRBD fs and I'm not sure how I can back them ...
-3
votes
3answers
862 views

Why is Qemu Virtual CPU on my kvm guests [closed]

can some one please clarify this. I am new to kvm and created two guest instances one linux and one windows. On both Guests, CPU is showing as QEMU virtual CPU,why is it so? if kvm utilizes ...
2
votes
0answers
737 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 ...
3
votes
2answers
3k views

How to start qemu directly in the console (*not* in curses or SDL)

I seem to recall being able to start qemu with only the terminal emulator output, with the graphic window disabled. And here I don't mean with the ncurses interface, that one is nice, but I want the ...
-1
votes
1answer
340 views

Cannot access Qemu/KVM virtual using console, VNC, or SSH, or access via network (IP range no longer valid) [closed]

I have the host sitting here next to me, so you'd think I'd have decent control of the guest. I should add that I have already attempted various other means, such as mounting the drive, but I have ...
0
votes
2answers
299 views

Can't get beyond boot screen after booting from CD in KVM

I've just installed KVM on Debian 6 64 bit and have created 2 guests and booted one of them. I can connect via VNC and I get the Debian CD boot options (text/graphical install). I have tried ...
1
vote
1answer
874 views

Setting up bridging for Qemu and routing for OpenVZ (venet) with multiple subnets on Debian Linux

So i've been searching the past couple days trying to figure out the best way to achieve this but still can't get it figured out. I have a debian server setup running Proxmox to host OpenVZ and Qemu ...
0
votes
1answer
240 views

See processes inside qemu

Sometimes a virtual machine inside kvm/qemu is saturated (load too high). Even a login (ssh) takes several seconds. But the host is still accessible. How can I investigate why the virtual machine is ...
1
vote
0answers
389 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 ...
5
votes
2answers
3k views

Filesystem passthrough functionality in Centos 6.2?

I have a CentOS 6.3 machine currently running 2 virtualized CentOS 6.2 machines via KVM/QEMU/Libvirt. I'm trying to setup filesystem passthrough between the guests and the host. However the option is ...
1
vote
3answers
525 views

Opening a Qemu/Xen file based VM Image (won't boot after upgrade)

Apart from one Virtual Host still running Xen/RHEL5, all our virtual capability is hosted on KVM hosts with LVM storage devices. I've stupidly attempted an Ubuntu full release upgrade on a guest ...
8
votes
1answer
1k 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 ...
0
votes
1answer
582 views

Can't get network bridging to work

I'm trying to make network bridging to work on a Debian squeeze (I'm experimenting in order to make a QEMU/KVM virtual machine that will be visible to the outside network as if it were a distinct ...
4
votes
0answers
848 views

QEMU: Solaris 11 / Sparc64 Guest on Linux / X86-64 Host [closed]

I'm trying to run a Solaris 11 / Sparc64 guest on a Linux/x86-64 host. I've cloned the qemu project and configured/compiled it with sparc64 support (./configure --target-list="sparc64-softmmu"). I've ...
2
votes
1answer
139 views

Install Windows with QEMU

I want to understand if it is possible to install Windows from Qemu to a physical HDD. I was trying to do that by doing something like this: qemu-system-x64 -m1024 -vnc :1 -hda /dev/sda -cdrom ...
-2
votes
1answer
512 views

Qemu on Mac instead of VirtualBox [closed]

Assuming I only want to use Linux as guest, are there any advantage in using Qemu instead of VB or other commercial solutions such as VM Fusion? I want to easy to ro tun Linux on my Mac without too ...
0
votes
2answers
193 views

make vnc server listen on guest's ip address

My host system has the IP 192.168.0.250. Now I want to create a kvm guest using a tap device (so the network card of the guest just acts like a "real" one). The guest has a static ip 192.168.0.249 ...
3
votes
2answers
202 views

kvm process has too large a memory footprint on host

I'm using latest ubuntu quantal and start a kvm guest which should have 2048 MB of memory. Now after a few hours I can see that the kvm process of this guest is around 2700 MB, so 700 MB more than the ...
0
votes
1answer
1k views

kvm with virtio scsi and rbd

I'm currently using virtio-blk but I'd like to change to the new virtio-scsi, especially because it supports trim/ discard. The host is an ubuntu quantal system (kernel 3.5.0, qemu 1.2.0). This is ...
2
votes
2answers
3k views

qemu-img: Could not open $FILE

I received a single-file VMDK from a vendor that has a virtual appliance for a particular product I'm interested in evaluating. We run a KVM solution (Proxmox) so I tried converting the file but on ...
0
votes
2answers
2k views

KVM/Qemu Guest Shutdown problems

on both host and guest running CentOS 6.3 with KVM/Qemu virtualization, I have the following scenarios: "virsh shutdown kvm1" did not shutdown at all. virsh lists guest as running. "service ...
6
votes
2answers
156 views

Accessing the partitions on an LVM volume

Suppose you have an LVM volume /dev/vg0/mylv. You have presented this as a virtual disk to a virtualised or emulated guest system. During installation the guest system sees it as /dev/sda and ...
-1
votes
1answer
561 views

Is it possible to pass /dev/urandom through from the host to a qemu/kvm guest?

I'd like to pass the host's /dev/urandom device through to a qemu/kvm virtual machine. Note that /dev/urandom is not seekable, so it's not possible to pass it through as a block device using -hda, ...
1
vote
2answers
3k views

Is there any way to shrink qcow2 image without converting it raw?

Is there any way to shrink qcow2 image without converting it raw? I cannot convert it to raw because I don't have disk space enough for raw image.
1
vote
1answer
206 views

Is it possible to run Windows as a Xen VM without VT, using Qemu-dm?

Is it possible to run windows as a virtual machine under Xen using qemu-dm? If so, how can it be done? Since Xen without VT technology supports only para-virtualization, can qemu-dm, the emulator ...
3
votes
2answers
9k views

conversion of a VMDK image with qemu-img failed with “error while reading sector 131072: Invalid argument”

I tried to convert a VMDK image found in a OVA file to the QCOW2 format with the qemu-img command but it failed with the error message qemu-img: error while reading sector 131072: Invalid argument ...
1
vote
2answers
3k views

does KVM raw images support preallocation?

I was trying to create a raw image with this command: qemu-img create -f raw -o size=200G,preallocation=metadata file.img but seem that it raw images doesn't support preallocation. if so why there ...
0
votes
1answer
265 views

KVM low network speed

I have a networking problem with KVM. There is only one VM on the server and port speed is 100 megabits per second But maximum download rate is about 1 megabytes per second and expected to be 10mb. ...
0
votes
2answers
904 views

Share CPU between two KVM VPS on a dedicated server

how can I share CPU between two KVM VPS on a dedicated server? assume that we have 8-core CPU on a dedicated server to get maximum performance for two VPS, should I assign 8 cores to each one of ...
0
votes
2answers
773 views

How to create LAN segments in qemu

I could successfully connect two different virtual machine ports directly using LAN segment feature in VMware workstation. Is there a way to do the same on qemu ? As of now i have created two qemu ...