Hi everyone, I’m one of the organisers of the CloudStack Collaboration Conference in Edinburgh, 18–20 November 2026, and wanted to invite people here working with KVM or evaluating a move from VMware.

For anyone unfamiliar with Apache CloudStack, it’s an open-source IaaS orchestration platform that can manage clusters of KVM hosts:

• KVM provides the hypervisor that runs your virtual machines.
• CloudStack provides central management of VM provisioning, host placement, storage allocation, networking, templates, snapshots, user accounts and self-service access through a UI and API.

Together, they provide an open-source option for building private or public clouds around KVM. For teams evaluating a VMware replacement, the discussion extends beyond converting VM disks to how you manage, network, protect and operate those workloads afterwards.

Several sessions address those practical details:

• Warm VMware-to-KVM migration: initial disk copies, changed-block synchronisation and final cutover. The talk examines VDDK, nbdkit, qemu-img, qemu-nbd, libnbd and nbdcopy, including performance, snapshot consistency and failure recovery.
• Destination storage: how migration write paths differ between qcow2 files, Ceph RBD and LINSTOR, plus sessions on storage integration improvements.
• Backup and recovery on KVM: Veeam integration engineering, incremental NAS backups and the native CloudStack DR framework under development.
• Hands-on KVM workshop: work in a live CloudStack environment to create VMs, configure networking, perform live migrations and explore snapshots and clones.

There’s also a production case study on migrating thousands of VMs from VMware to CloudStack.

18 November: hackathon
19–20 November: sessions, workshops and live labs
Venue: John McIntyre Conference Centre, Edinburgh

If you’re considering CloudStack to manage a KVM environment, I’d love to welcome you.

Technical agenda | Registration

FREE TICKET IS AVAILABLE ON REQUEST

Whenever i try to install ubtunu 24.04 i get a a graphicla/bios (i think bios) error. Any help?

Hello Guru's, I have a few questions, please help me answer them:

1. If I have existing full fledge old VMs on my existing KVM hosts (VM's not inside the PODs), will I be to manage them via Kubevirt?
2. If I have a RHOV environment, is it necessary for me to use Kubevirt to create a VM? If yes, why, if not, then when to use KubeVirt to create VMs?
3. What is the difference between a regular VM and a VM created via Kubevirt?

Also, I'd love to get your candid take: What aspect of KubeVirt has impressed you the most, and where do you feel it faces the biggest friction points or challenges?

Would my host machine break, crash, be corrupted etc? Would I have to re-install my distro? What would happen if i messed up my host machine with setting up the VM?

Fyi: I use Pop_Os! .

Hi r/kvm,

I have been working on WebKVM, an open-source, web-based management panel for KVM/QEMU and Incus on headless Linux hosts.

While virsh is great for scripting and virt-manager is the traditional GUI, running virt-manager over SSH X11/Wayland forwarding or Spice tunnels can feel clunky. I wanted a fast, native web interface that talks directly to the Libvirt API without turning the host into a heavyweight appliance.

Architecture and Features:

• Direct Libvirt Integration: Connects cleanly to qemu:///system via native Libvirt bindings in Go, leaving all guest domain XML definitions 100% standard and manageable via virsh in the terminal.
• Instant CoW Storage: Integrated template pool allowing 1-second guest provisioning using QCOW2 Copy-on-Write backing files from official cloud images (Debian, Ubuntu, AlmaLinux, Arch, etc.).
• Optimized Hardware Profiles: Built-in domain templates configured with optimal virtual hardware:
  • Modern Linux: Q35 chipset, UEFI (OVMF), VirtIO-SCSI/VirtIO-BLK, and VirtIO-Net.
  • Windows 11: Emulated TPM 2.0 (swtpm) and OVMF Secure Boot out of the box.
  • BSD / Legacy: BIOS (SeaBIOS) and compatible storage/NIC fallback emulation.
• Network Management: Web configuration for Linux bridges (vmbr0), isolated vSwitches, and NAT bridges (vmbr1) with automated dnsmasq DHCP lease tracking.
• Integrated Consoles: Real-time embedded noVNC graphical displays, serial consoles, and direct host terminal access.
• Dual Engine: Alongside full KVM/QEMU VMs, it integrates native support for Incus (LXC) system containers.

Performance and Resource Usage:

• Memory: Written entirely in Go. Consumes roughly 15 MB to 30 MB RAM at idle and stays under ~70 MB during multi-guest operations.
• CPU: ~0% idle overhead. CPU cycles are only consumed when streaming live noVNC guest display sessions.

Current State and Feedback:

• Solo Maintainer: I am developing and testing WebKVM on my own across vanilla Linux hosts (Ubuntu, Debian, Fedora, Arch). There may still be edge cases or bugs.
• 100% Free and Open-Source: No enterprise licenses, telemetry paywalls, or feature locking.
• Multi-language: UI currently supports English, Spanish, and Catalan.

GitHub Repository:https://github.com/Slaker19/webkvm

I would love to get feedback from other KVM users regarding storage pools, domain XML generation options, or features you would like to see implemented!

Hello

I have a laptop with fedora 44 and kde plasma 6.7. I have an intel iGPU and an NVIDIA dedicated GPU.

I would like to setup my system so that my fedora host has access to both the iGPU and dGPU but when I start my win11 vm, I want the iGPU to stay with fedora and the dGPU to be passed through to the win11 vm.

My main problem is that kwin_wayland keeps using the dGPU (I think because it wants access to the hdmi port on the dGPU) even though I am trying to keep it from doing so. Because the dGPU is being used, I cannot activate the vfio driver and pass the device to the win11 vm.

Is there any guide or advice available to set this up?

Thanks in advance

Out of ideas for debugging this.

Debian 12 host, Win 10 guest - a home setup with an OpenWRT router. I used macvtap with it's own physical nic for guest networking. The guest shows up on router with it's own IP as expected. I can use other devices on local subnet to ping and load webpages from both host and guest but not between host and guest. traceroute host to guest says: [host] (192.168.1.133) 3077.647 ms !H 3077.586 ms !H 3077.567 ms !H. tracert on windows guest to host just gets a lot of "request timed out".

Pretty sure VPNs not affecting local subnet but: Router set up to send everything through VPN#1 but I excluded host and a windows laptop. Host has VPN#2 (different vpn providers) and the windows laptop has no vpn. A phone using VPN#1 and the windows laptop with no VPN can both ping/access webservers on both host and guest so I'm thinking that means VPNs aren't the issue.

ive been here for hours trying to do the simple task of installing windows 11 on kvm using cockpit and ive given up. no matter what i do i cant get it to boot. its impossible. ive been watching youtube videos asking LLMs and

What do these options mean? I want to run the vm alongside my main os (pop-os) and not replace my main OS. Like I want to run a second vm in like a seperate window like an add on. Not replacing my primary Pop-os distro.

I am going to install archcraft and hopefully a few other arch distros

Specs shown in picture.

note- I will be posting multiple images, furthur ones I will link to images and ask in the main comments for help instead of making like 20 posts lol.

edit: Any specific youtube videos that can help as well? Totally open to youtube videos but I would like to get help with the photos i post here and in the comments too so I can go step by step and learn.

thx!

noob question here !

So I got the idea of virbr0 being the switch / dedicated router / NAT for all my vm on kvm

But now I need to add vlan on some of those VM

Should I add a vm based on Open vSwitch in front of virbr0, and then just connect my vm on it so I can then manage my vlan thourhg Open vSwitch, or can I / should I use the virbr0 network and configure it in some way to manage the vlan on my network ?

Edit : Also I've read the documentation https://wiki.libvirt.org/VirtualNetworking.html and now I'm even more confused since it's clearly supposed to be a switch but it can't be configured as a switch.

I am considering leaving Windows. As of right now I have an Nvidia 5080 (wish I could afford a rtx 6000pro) with srv-io enabled in my bios.

I use wsl right now for pytorch and cuda stuff with hyper-v for my various unrelated virtual machines.

I need specific versions of python and cuda. On Windows this is not a problem with wsl I can set different containers with different versions.

My question is without a pro series card can I use kvm for different OS versions and frameworks separate from my host?

Radxa has unveiled the Linkr, a compact remote-control device for accessing computers, servers, and development boards through a web browser. The unit combines HDMI video capture with USB keyboard and mouse emulation, allowing users to view and operate a target system without connecting a dedicated monitor, keyboard, or mouse.

https://linuxgizmos.com/radxa-linkr-brings-remote-kvm-access-and-tailscale-support-to-a-thumb-sized-device/

Hi, I am new to KVM/QEMU and am struggling to understand the networking options and how to configure them properly. I am moving away from HyperV, and am trying to understand what options in libvirt line up with the needed configurations:

- Host has 2 physical NICs

- NIC 1 (hyperv config - External network, host access disabled) single guest needs direct access to the network the physical adapter is connected to, and ONLY that network. No access to host.

- NIC 2 (hyperv config - External network, shared host access) multiple guests need direct access to the network this NIC is connected to, the host, and other guests on the same network.

It is my understanding that for my NIC 2 scenario, I need to set up a bridge connection on the host connected to the NIC. However, I cannot seem to find a clear answer as to the NIC 1 scenario.

Could someone please confirm how I can properly achieve both goals, and provide resources for configuring each correctly?

Thank you.

Guest: Windows 11
Software: VirtManager KVM/QEMU

Issue: Specifically on my Windows 11 VM, the network speeds are substantially slower than my other Linux VMs and my host. On my host, I get around ~1000 mbps, same for my other Linux VMs--however, on my windows VM, I get around 10mbps, or roughly 1% of my host's network speed.

all VMs are properly configured so that the Network is NAT using the virtio model. In addition to that, I have the up-to-date virtio-win drivers set up on the Windows 11 virtual machine. The windows 11 virtual machine recognizes the Red Hat Virtio Ethernet drivers and are properly using them with a duplex max supported speed of 10gbp/s.

I'm very confused as to why this is only occurring on my Windows VM whereas this issue is nonexistent on my Linux VMs. There's no differences in the XML regarding the CPU XML and the NAT XML between the VMs.

I tried adding vhost with a queue of 16 for each core, switching the driver to e1000e and hypervisor default--none of which saw any improvement. I also tried reinstalling the virtio-win drivers which did nothing.

Finally, I attempted to disable a bunch of offloading properties in the Device Manager, and disabled ipv6 entirely and set MTU lower. None of that made any difference (did not worsen it nor improve it).

Any ideas, folks? All of the VMs have a dGPU (Same dGPU shared between them all, so only one can be accessed at a time).

I should also mention, that the network speeds on the host system are stable--no drops or high latency. The network drivers on the host are all up-to-date and working perfectly.

I really want shared folders and resolution working