Questions tagged [qemu]
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.
636
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GRE and QEMU and TAP
HOST SERVER
ENO2 has Internal IP 192.168.55.128 and External IP 200.100.100.100
TAP0 has Internal IP 192.168.10.1
GRE1 has Internal IP 10.10.4.243 and External IP 165.100.100.100
VM SERVER
eth1 has ...
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Enable ethtool statistics in a QEMU CentOS Guest OS
I have a network interface available in a QEMU Guest OS running CentOS 7, and on the Host OS side it reports as:
$ virsh domiflist --domain mydomain
Interface Type Source Model MAC
-...
9
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4
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What is the the purpose of using paravirtualization if there is a hardware assisted virtualization?
I am doing a research about QEMU/KVM and Firecracker/KVM.
As far as I understood, both Firecracker and QEMU communicates with KVM to eventually benefit hardware assisted virtualization by changing CPU ...
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126
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Wireless-Bridge on a ubuntu 22.04 (netplan) for three QEMU VMs
I do have an apparently trivial, but it is rather an ambitious project.
Wishing to run three ubuntu 22.04 VMs on my laptop, installing and configuring kubernetes for an initial learning phase with the ...
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42
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Qemu linux guest disconnected randomly
I have a mac m1 with an arm processor and I want to use Linux sometimes.
For this I followed this guide and everything is working as expected and I have a working Linux guest. The only thing I added ...
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164
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How do I remove cloud-init backing image from my VM?
I am moving a VM from Ubuntu 22.04.3 LTS KVM host to a RHEL 8.9 Ootpa KVM host.
When I try to start the VM on the destination (RHEL) host I see,
error: Cannot access backing file '/var/iso/jammy-...
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1
answer
47
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Set Maximum cpu qemu/libvirt almalinux
I want ask to increase supported CPU core on qemu kvm. When I creating new VM I see error like below
error: internal error: QEMU unexpectedly closed the monitor (vm='ID'):
qemu-system-x86_64: -accel ...
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1
answer
31
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Run QEMU command with cron
I have a machine that, aside of other services, needs to run a server VM. I'm running the VM with:
qemu-system-x86_64 -nographic \
-enable-kvm \
-m 8G \
-smp 2 \
-hda gw_disk.qcow2
...
2
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0
answers
209
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How to sucessfully import an .ova vm exported from ovirt/kvm (Red Hat OS)?
So, I was given an .ova file. This is exported from a server using a combination of KVM/QEMU and ovirt technologie - the server runs RedHat and I want to import this .ova file into vmware or ...
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1
answer
221
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Cannot access deb.debian.org from VM after port forwarding using /etc/libvirt/hooks/qemu
Setup
On host server with Debian Bookworm I created two VM-s (pserver 192.168.122.227 and pagent-1 192.168.122.126) via cockpit (kvm). Both of them are running Debian Bullseye. I am using default ...
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66
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Can qcow2 overlay get committed back into raw backing file?
I am trying to design a system utilizing the btrfs filesystem and libvirt.
btrfs has copy-on-write (COW) already, it's very easy to do snapshots and it's very efficient to transfer the snapshot to a ...
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0
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127
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How to set default disk image format in Cockpit/QEMU
I create my virtual machines on Debian 12 with Linux Cockpit 287-1 which uses QEMU/KVM for virtualization. If I create a VM, the default disk format is always in RAW-format. However, due to some ...
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179
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KVM virt-install issue
I want to run arch linux as guest but after virt-install screen is stuck at console Escape character is ^] (Ctrl + ]).However VMs install by virt-manager are working fine and console is also working ...
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1
answer
720
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Changing KVM VM listening on 5901 to some other port
OK this is rather silly, but real problem.
vncserver keeps binding on 5902 port. That is because qemu is listening on 5900 and 5901:
% netstat -lntup
Active Internet connections (only servers)
Proto ...
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0
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348
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After converting Windows guest OS .vmdk file to .qcow2 and hosting to KVM gives "No Bootable Device"
We are migrating guest VM from VMware 7 to KVM (installed on Ubuntu 22.04 LTS).
We have achieved success in migrating all Ubuntu guest VM from VMware to KVM by converting the vmdk disk to qcow2.
...
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1
answer
402
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Making all Linux network interface (bridged) in a qemu VM use dhcp
I have a small application which takes in kernel code, and spins up VMs. I've been using this for kernel development. It is helpful and very fast when I want to spin up VMs with different kernel codes....
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2
answers
165
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How to access service from virtual machine of another machine in local network?
I have two Ubuntu machines A and B in my local network.
Computer B has an openmediavault instance set up via KVM.
Computer B has the IP address 192.168.177.58, the openmediavault instance provides a ...
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0
answers
203
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Machine type issue when migrating KVM VMs with live snapshots from Debian to Ubuntu
I'm trying to migrate around 40 KVM VMs (containing a few hundred live snapshots mostly used for automated testing on Windows) from a Ubuntu 22 server to a Debian 11 server. The machine type of most ...
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180
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How to make KVM guest configs persistent across reboots/shutdown
I create a KVM Guest VM (virsh define a.xml, virsh start a.xml). Guest uses pre-configured/pre-made QCOW2 disk image, which represents a virtual router (Arista vEOS). Host is Redhat 9.1. Guest is ...
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1
answer
461
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Why qemu fails to start host only network on loopback when there's no other network on host?
Starting qemu-system-x86_64 with -nic user,ipv6=off,hostfwd=tcp::9022-:22
With only the lo interface (with 127.0.0.1 associated to it) present on the host, the vm will start, but any daemon trying to ...
2
votes
1
answer
2k
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QEMU SMP options
I'm trying to understand the QEMU smp option.
Currently I have set it to:
smp 4
As far as I understand that should create 4 vCPU (with 1 core and 1 thread I suppose).
Would it be better for ...
1
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1
answer
1k
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Determine QEMU KVM overhead?
My guest OS shows about 5 percent CPU usage, but my host machine shows the QEMU process taking about 25 percent.
I'm trying to understand where this difference comes from, as I am using KVM ...
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0
answers
61
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QEMU load average vs cpu count
When I configure more CPU cores, the load average in my Guest OS as shown by top also increases linearly.
I'm trying to understand why this happens, because I expected either the opposite or at least ...
2
votes
1
answer
1k
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Dynamic CPU allocation/scaling in QEMU KVM
How can I dynamically allocate/scale CPU resources to my QEMU VM according to the workload of the VM? Would this require a script? Is it even possible to change CPU allocation at runtime?
I have a ...
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0
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14
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Can you use virsh to reset vm id sequence? [duplicate]
Question in regards to "Id" for running VMs, using virsh running local Qemu VMs.
command virsh list will bring up a list of the current running VMs defined, eg,
Id Name State
--------------...
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0
answers
155
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qemu set different dynamic ip address for each machine
I need to run about 7 virtual machines via qemu at the same time. The problem is that they all have the same public IP address as the host. Is there any way to give them different ip addresses? host ...
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242
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How to make Ubuntu VM available to multiple users in the cloud?
I have a design technical question.
Let me describe the use case first:
I have 20 students. My idea is that they all can run a full Ubuntu Desktop from within their web browser. Everyone should have ...
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126
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Fedora does not boot when it is installed / virtualized using virt-manager and later booted using the qemu parameters (using /dev/sdd as disk)
I'm on Debian 11 (where I'm using the default qemu version 5.2) and I'm trying to boot Fedora 37 using the following qemu commands :
/usr/bin/./qemu-system-x86_64
-enable-kvm
-m 8G
-machine q35,accel=...
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1
answer
481
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How to properly make a backup of a virtual machine using QEMU only
This questions asks how one can make a backup of a live virtual machine.
The accepted answer says it is possible with QEMU/libvirt.
My question (since the answer doesn't explain it) is how to do a ...
1
vote
1
answer
605
views
How to use more then 2GB of ram when using running a nested BIOS VM using KVM
I have a Linux host running Debian 11 and on that host, I have a Ubuntu 22.04 VM. Inside that VM I want to run a Windows 10 VM using nested virtualization. The ubuntu VM is booted using EFI and nested ...
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1
answer
368
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Occasional packet loss between bridge interfaces
I have two virtualization servers based on libvirt and KVM. And sometimes I see packages get lost on one particular virtual machine. After restarting the virtualization host this problem is solved, ...
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1
answer
122
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Can I use OpenStack Rocky with a neoverse-n1?
Situation: For now, I'm stuck on OpenStack Rocky on Ubuntu 18.04.6 and I have some beefy Neoverse-n1 hardware (aarch64, 64-core, 1TB memory) to integrate. Can I accomplish this with on my current OS ...
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1
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147
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Three virtio-blk devices crashing Windows 10 VM
If three virtio-blk devices are added VM is crashing in the middle of the Windows 10 boot. The attached blockdev has no influence. VM is working fine using two virtio-blk.
qemu-system-x86_64 \
...
-...
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0
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178
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Backing encrypted drive
Creating a backing image for the master image that is encrypted using LUKS:
qemu-img create -f qcow2 -b dev.qcow2 -F qcow2 -o encrypt.format=luks,encrypt.key-secret=dev --object secret,id=dev,data='...
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1
answer
194
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How to read qemu fw_cfg value in windows guest?
Unable to find information about how to read -fw_cfg value in windows guest with the help of this: https://github.com/virtio-win/kvm-guest-drivers-windows/tree/master/fwcfg
Related question: https://...
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0
answers
138
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How do I force Virt-Manager to use the hosts' llvmpipe renderer so the guests get to use 3D acceleration?
I'm using virt-manager and set "3D Acceleration" as per what was recommended, but I'm getting this error:
qemu_gl_create_compile_shader: compile vertex error 0:2(10): error: GLSL ES 3.00 is ...
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1
answer
3k
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How to connect to UTM VM exposed port from the host? [closed]
I have a windows VM set up with UTM on my M1 mac but cannot access it event though it is set on shared network in the preferences.
I've tried localhost:5432, 127.0.0.1:5432... with no success.
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1
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497
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How to start a Proxmox VM on Windows w/ Qemu
I'm trying to start a Proxmox VM using the qcow2 image on Windows using Qemu, however I can't figure out the correct parameters to start the machine.
Based on my settings in the Proxmox Web UI:
I ...
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0
answers
465
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QEMU boot with no progress for quite long after using the -enable-kvm option
I just wanna start a vm based on x86_64 via qemu, everything goes as expected(e.g. showing the console and login part) when I run the command below
qemu-system-x86_64 \
-nographic \
-smp 4 \
-kernel ~/...
1
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0
answers
774
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how to make two qemu guests communicate between them as well as with the host
I'm on MacOS with apple silicon. I'm tring to set up a vangrant environment of two nodes which both should be able to see each other and be reachable by the host.
For that, this is the Vagrantfile I'm ...
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0
answers
2k
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Error starting domain: unsupported configuration: host doesn't support passthrough of host PCI devices - fedora 37
I added the section in the xml file of the VM win10 and I got the following error:
Error starting domain: unsupported configuration: host doesn't support passthrough of host PCI devices
when trying to ...
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1
answer
239
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Windows asking me to sign in with a company email?
Windows is asking me to sign in with my company's email, problem is I don't have one and nor is the company related to me whatsoever. I am trying to run Windows LTSC on QEMU. What gives?
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0
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82
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"Welcome to Intellek" when trying to install Windows LTSC 2021 in Qemu [duplicate]
On the "Account" stage, it says "Welcome to Intellek" and prompts me to enter my email for Intellek. I do not know what that is, a search reveals it is some company? I downloaded ...
0
votes
1
answer
210
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Cache mechanisme in kubernetes
I've got the next setup:
Proxmox 7.2
CEPH 16.2.9
K3S v1.23.15+k3s1
CEPH CSI v3.7.2
CEPH using as RBD-storage for QEMU images and K8S PVC. When I do disk benchmark in QEMU I've got the next results:
...
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1
answer
2k
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Ubuntu 22 No ACPI DMAR table found, IOMMU either disabled in BIOS or not supported by this hardware platform on nested VM
I am using ubuntu 22.04 LTS minimal server. My host server is set up with kvm and is functioning well. All tests pass when running virt-host-validate.
When I create. virtual machine i want this to ...
0
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3
answers
629
views
Before-snapshot script hook for Windows guest on Proxmox?
I have a Proxmox server setup with a Windows 10 guest that will be running MSSQL Express. The Windows guest has QEMU guest agent installed and working. For backups, I have a separate server running ...
2
votes
3
answers
2k
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Disadvantages of using ZFS recordsize 16k instead of 128k
I'm using Proxmox on a dedicated server. For production I'm still using ext4, but I decided to start messing around with ZFS.
So I have created two separate ZFS storage pools with diffrent recordsizes:...
1
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0
answers
104
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RTSP Stream Cannot Be Accessed from KVM Guest using NAT - iptables forwarding
How should iptables on the host be configured to allow rtsp:// traffic from a KVM guest that initiated the connection via a NAT network interface?
It doesn't appear to be a simple mapping. I don't ...
0
votes
1
answer
352
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Trying to install RHEL 7 under QEMU s390x emulation
I'm evaluating the use of QEMU to create s390x Linux virtual machines for use in software builds. I've had some success creating machines using newer Linux distributions such as RHEL 8 and Ubuntu 20, ...
2
votes
1
answer
3k
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Understanding Current/Maximum allocation of VirtManager (LibVirt)
When I first saw the UI in VirtManager, I thought "Maximum" is the amount of ram that appears to the guest, and "Current" is the reserved RAM when the VM starts. I thought that ...