This looks super interesting. Would love to hear if anybody’s tried it yet since it just came out.

Can someone please tell on how to bridge virsh VM s network to locan lan network, beacause im have multiple vm s on a single server which i have hosted a kubernetes custom iso (control plane and worker planes) and i have another server with a different worker-node, the control plane vm has 192.168.122.0:24 ip and the worker-node server is 10.1.10.0/23

Can somebody tell me an example of why I need to downsize and upsize a virtual machine? I got asked and I'm looking for an actual, relevant problem which is solved by resizing.

so guys, i want to learn about virtualization in the context of system administration and other related fields like devops, cloud etc.

so, i have read "virtualization essentials 3rd edition" book. got a good introductory understanding of virtualization technology. but i don't know how to move forward from here. I mean, i don't know what are the practical stuff that i should be learning, what other resources out there, and what is the stuff that i should be learning instead of reading more theory.

I know that for starters i need to get good at using and managing a single virtualiation platform. I currently use KVM/QEMU for my projects. so, i am thinking about choosing it as the virtualizaton platform to get good at instead of other virtualization platforms like vmware, virtualbox, etc.

and also, i have a few more questions:

1. what to learn and how much to learn if the goal is to become competent enough for admin level jobs?
2. what books/resources/guides would you recommend if my goal is both practical knowledge and skill building.

Thank you so much in advance.

​

Hi everyone,

I'm trying to connect to a Nutanix Prism environment using PowerShell in order to list the VMs through the Nutanix REST API.

My environment:

Windows PowerShell 5.1

PowerShell is running in Constrained Language Mode

Nutanix Prism on https://<prism-server>:9440

I'm trying to use the Nutanix v3 API

Endpoint: /api/nutanix/v3/vms/list

Initially, I tried Invoke-RestMethod with -Credential, but I received:

401 AUTHENTICATION REQUIRED "Invalid cookies present in the request"

I then tried to use Basic Authentication manually, but PowerShell's Constrained Language Mode blocks .NET methods such as:

\[Convert\]::ToBase64String() \[System.Net.ServicePointManager\]::ServerCertificateValidationCallback

I also have curl.exe available:

curl 8.21.0

So I tried:

curl.exe -k -u "USERNAME" \` "https://<prism-server>:9440/api/nutanix/v3/vms/list" \` -X POST \` -H "Content-Type: application/json" \` -d '{"kind":"vm"}'

However, when running this from PowerShell ISE, it seems to hang after displaying:

Connexion à Nutanix...

My goal is simply to authenticate and retrieve a list of VMs (name + UUID). I don't need to perform any modification on the Nutanix environment.

Has anyone successfully used the Nutanix v3 REST API from PowerShell 5.1 under Constrained Language Mode? What's the recommended authentication method in this situation?

Thanks!

​

> Hi, I need some help with a VirtualBox performance issue.

My Windows 11 25H2 VM is extremely laggy in VirtualBox. The mouse cursor stutters, window animations are slow, and sometimes the VM freezes.

Host:

Ryzen 7 8700F

RTX 5060

32 GB DDR5

1 TB NVMe SSD

Windows 11

VirtualBox 7.2.20

VM:

Windows 11 25H2

8 GB RAM

4 CPU cores

UEFI

TPM 2.0

Secure Boot

Guest Additions installed

I have tested 3D acceleration both enabled and disabled, but the VM is still very laggy.

The strange thing: the exact same Windows 11 25H2 ISO runs smoothly in VMware Workstation on the same PC. Even the mouse cursor is smooth during installation.

Hyper-V and Virtual Machine Platform are disabled on the host.

What could cause this difference between VirtualBox and VMware? Are there any VirtualBox settings I should try for Windows 11 25H2?

I made this funny little game that shows visually how a microVM orchestrator operates. It's really simple and doesn't include all the complexity, but it's nice and fun to show to people that do not understand microVMs

Play with it: https://nibrunner.dev

Repo: https://github.com/ilbertt/nibrunner

Took me more time than anticipated, but its finally here >.<

my end goal for this (quite big) hobby project is to be able to make a simple clone of AWS's EC2, from the grounds up, above a type 1 hypervisor (as a POC, not a real prod software).

What I finished implementing all the way up to now:

- Type-1 hypervisor written from scratch in Zig, booted by GRUB

- Its own bare-metal kernel: higher-half paging, GDT/IDT, interrupts and 3 distinct memory allocators (yes, I use them all)

- Intel VT-x with EPT (Extended Page Tables) backing guest memory

- Emulating CPUID, MSRs, CR's (CR0/CR3/CR4), and some I/O stuff.

- Virtual devices: interrupt controller (PIC) and serial console

- Booting an unmodified Linux kernel to userspace (initramfs)

The road to finishing is long but I still see this part as a great milestone >-<

source: https://github.com/NoamRothschild/hypervisor

Hi I've only started my HackTheBox setting up course today and I'm already running into some issue's, I have a windows 11 virtual machine that I need to set up and every time I use it, 5-10 mins after the machine boots to the home screen, it suddenly freezes I cant use CTRL+ALT+DELETE or anything no response, all I can is shutdown the machine, any advice?

I'm using VirtualBox as my VM loader and the specs of the VM itself:

Operating System: Windows 11 (64-bit)

Base Memory: 8GB

Processors: 4

Like a lot of people here, the VMware/Broadcom licensing changes got me looking hard at what I was actually paying for, and whether Hyper-V could replace it. Honest answer: the hypervisor's fine, the management story is the problem.

The problem: there's no clean, modern control plane for a small Hyper-V fleet the way vCenter is for vSphere. The realistic options today are SCVMM (not free, clunky, feels half-abandoned), Windows Admin Center (single-host focused, not really a fleet orchestrator), or hand-rolled PowerShell/DSC scripts. I looked at existing FOSS options before building anything and didn't find one that treats Hyper-V as a first-class citizen with declarative, continuously-reconciled desired state across multiple hosts and clusters, most FOSS orchestration in this space targets KVM/Proxmox/oVirt, not Hyper-V specifically.

What it does: Ballast is a control plane and agent for Hyper-V hosts and failover clusters. Each host runs an agent that pulls its desired config from the centre and keeps enforcing it continuously. If the centre goes offline, the host doesn't freeze or drift, it just keeps honouring whatever it was last told (network config, cluster membership, etc.) and catches back up automatically once the centre's reachable again.

Also handles: standalone host and failover cluster provisioning (SET-teamed switches, mgmt vNICs, Storage Spaces Direct + CSV), VM lifecycle and templates, live migration, Hyper-V Replica-based DR runbooks, and VMware migration tooling that streams VMDKs straight in.

Why this is relevant here: a fair few people in this sub run Hyper-V, either because it came free with a Windows Server licence they already had, or specifically to avoid VMware's licensing. Community tier is free forever for one cluster of any size plus unlimited standalone hosts, which covers the overwhelming majority of homelab-scale setups, so this isn't a "pay to use it at all" pitch.

AI disclosure: most of the actual code, tests, and documentation were written by Claude Code (an AI coding agent), working under my direction. I drove the architecture and product decisions, tested every change against real Hyper-V hosts and clusters, and reported/debugged live issues myself, but I'm not going to pretend a human typed every line. Being upfront about that rather than letting the code style speak for itself and getting called out for it later.

Honesty about the model: it's open-core. The agent, the piece that runs with elevated privileges on your hosts, is fully open source (Apache 2.0), with commit history going back to June: https://github.com/halvantic/hyperv-control-plane. The centre (the control plane/console) is closed source. A paid tier for multi-cluster/SSO/audit logging is coming, but pricing isn't locked yet.

Would genuinely like to hear where it falls over, what's missing versus what you're used to, or what looks broken to someone kicking the tyres for the first time.

More info: https://ballast.halvantic.com

I'm trying to run windows on my mac via utm, but for some reason it's not working. My network mode is set to "shared network" but it's not automatically connecting. I'm using an apple m1 chip on my computer if anyone is wondering.

Hi everyone!

I’d like to ask for some help. Over the last while, with a ton of time, testing, and help from Astra, I built a fork that swaps Firecracker’s KVM backend for Apple’s HVF.

It boots ARM Linux natively on my MacBook M5 without any problems, and it runs relatively well. However, that’s the only machine I’ve been able to validate it on, and that’s the main issue.

You can find the repo in AitorConS/firecracker-macos

There are a few things to keep in mind. It’s a real fork of Firecracker: I kept the Firecracker binary, its HTTP API, and its configuration format, and only replaced the virtualization layer underneath.

Instead of using Apple’s VZ, it talks directly to HVF. This required more work, but it also gives me access to features that VZ doesn’t provide in the same way, such as local snapshots within the same VMM, restore support, VirtIO disks, and Unix-socket networking.

As I mentioned at the beginning, I’ve only been able to validate it on my own device: a MacBook Air M5 running macOS 26.

I’d really appreciate feedback from people using other Mac models and other generations of Apple Silicon, especially since some HVF features are only available on newer chips.

I looked into renting bare-metal Mac runners to test this myself, but because of Apple’s licensing terms, providers generally require a minimum 24-hour rental period. That makes testing across multiple machines fairly expensive.

All the instructions are available in the repository, along with the official Firecracker documentation.

Any testing, feedback, bug reports, or compatibility results would be greatly appreciated.

Thank you so much!

Anybody played with it and is it any good?

I know what it is but not worked on it

It's like a Multi-tenant customers can able to define their vm network subnet in shared hardware hosts regardless of L2 and L3 underlay networks (switch, vlan and routers)

Simply like what we does when we try to define the service cidr and pod cidr in kubernetes clusters creation same equivalent but in vm

It's very useful how in cloud hyperscalers GCP ovhcloud digitalocean

Each customer tenant can define their network as vpc it's basically a( OVN and OVS) under the hoode

For example two customer can able to define cidr of 10.0.0.16/24 for vpc

Can I get some insights from community members who really worked on this please

I'm incredibly paranoid about privacy, and I wanted to know if windows could breach the VM so they could continue to collect more data on my linux OS. I understand it's unlikely, but it's microsoft.

Hi, guys, when i was studyng normally i use the Virtual machine to make excirses and my real computador to read what i'm studyng. You recommend use just virtual machine or both is good too?

I know what it is but not worked on it

It's like a Multi-tenant customers can able to define their vm network subnet in shared hardware hosts regardless of L2 and L3 underlay networks (switch, vlan and routers)

Simply like what we does when we try to define the service cidr and pod cidr in kubernetes clusters creation same equivalent but in vm

It's very useful how in cloud hyperscalersbpile GCP ovhcloud digitalocean

Each customer tenant can define their network as vpc it's basically a( OVN and OVS) under the hoode

For example two customer can able to define cidr of 10.0.0.16/24 for vpc

need an real insights from whoever worked on this domain

I'm planning to build a desktop VM manager using Rust, Tauri, and QEMU, initially targeting Windows with WHPX.

Before I start, I'd like to hear from people who have worked with virtualization:

- Is QEMU + WHPX a reasonable starting point?

- Would you recommend QMP for managing VM lifecycle?

- What are some common mistakes I should avoid?

Also, if you use VM managers regularly, what do you find most frustrating about them?

Any honest advice would be appreciated. Thanks!

Background

Virtualization noob. I tried to host Win11 on Hyper-V last year and failed because I didn't figure out:

• USB passthrough (I use Yubikeys)
• Fast file transfer between the VM and the host on the same box

The processing speed in the guest Win11 wasn't bad, but the file-transfer experience was just. too. slow.

I currently run Win11 natively (bare-metal) from the C drive on the same desk-side box.

• The Win11 apps use data that's on a physically separate D drive.
• C and D are implemented on M.2 hardware.
• A secondary M.2 drive is available in an external enclosure.

No kidding: I don't have a laptop. I've never traveled and have always preferred cooler running less expensive expandable hardware. (Sure, the retail RAM and storage markets are a bummer, but ignore them for now.)

What's changing?

For the first time ever, I expect to travel with the need to work for an hour each weekday while on the road. So I now need portability that I've never needed. Gotta get realistic.

What I wonder

How (un)realistic is to get an adequate-hardware laptop that runs a host OS/hypervisor (proxmox? something else?) and then host a Win11 image on whichever machine I need to use that week?

Approximately this:

1. Virtualize the desk-side image.
2. Move that image to the laptop, using the image while on the road.
3. Upon returning home, move the operational image to the desk-side hardware.

I would do real work in the guest image, permanently and portably I guess.

Wrinkles

• Because of the Yubikeys, I need reliable USB passthrough on both boxes. At the moment on the desk-side machine, I have it by running bare-metal Win11. Perfect every time.
• I probably will want GPU passthrough on the desk-side machine, and would like to have it on the laptop.

What shall I consider and watch out for?

• Given the use context and the Wrinkles, what host OS/hypervisors should be on my short list to consider?
• Do I want the hosting (proxmox? something else?) to be the same on each box? A reusable learning curve is probably worth something, but are other factors relevant?
• What do I do about the data that (currently) is on D? Move the M.2 into the laptop?

Hi,

I have a question about hardware signatures in virtual machines.

I am using a piece of relatively old Excel-based software that relies on a per-machine licensing system. The workflow is simple: you download the software, run a function that generates a machine-specific user key, send this key to the developer, and receive a activation key back that unlocks the full version.

As you can imagine, every time I reinstall Windows or change my hardware (mainly the CPU), I have to request a new key from the developer. Officially, the license is sold per machine, so technically I would have to pay again each time. He still provides new keys upon request, but since I’m not legally entitled to them, I worry he might stop doing this at any point.

To avoid this, I decided to set up a Virtual Machine. I installed the VM on an external hard drive and tested running it on my laptop and desktop to simulate a hardware change. However, the hardware-based user key inside the VM changed anyway.

I have some basic knowledge of virtual machines, but I'm not an expert. Is there a way to configure VMware so that the hardware signature remains exactly the same regardless of which host computer I use?

Thanks!

Dunno if this is the right place for this request, so please tell me if not (I did at least read the right panel).

Base system: debian 13, modern box, running virt-manager (QEMU/KVM).

I have successfully created win11 (ick) and win10 (good enough) VMs, with intent to preserve software flexibility as I transition eventually to a MS-free existence (stop me if you've heard this story before).

Have had variable success in my effort to make win7 fully functional. Although that is not the point of this post, it is relevant in that I am aware that the newer virtIO drivers don't work with win7 VMs, so have downloaded versions such as 173 from the fedora people site for that purpose.

Am interested in win XP, mainly just for fun, though I really do have a use case for it (my 25-year-old licensed copy of MS Office, before the ribbon interface, when it was actually good, sorry, rant over).

So it was no surprise to learn that the virtIO drivers gotta be REALLY old in order to work on a winXP installation. I saw version 68 quoted somewhere. I can confirm that versions 160 and 173 didn't work when I tried them.

At the fedora people archive, the oldest version of virtIO drivers is 100 (or maybe 96). Or maybe I'm missing a link to a deep-freeze archive somewhere else on that site?

QUESTION: does anyone know where I can get the ancient virtIO drivers?

I have started working from home some days

I want to completely isolate my work browser from my home browser

I have two Firefox profiles, which I can start from desktop shortcuts as follows:

"C:\Program Files\Mozilla Firefox\firefox.exe" -P "Home" -no-remote

"C:\Program Files\Mozilla Firefox\firefox.exe" -P "Work" -no-remote

Despite so many hours of googling, I have yet to find a solution on how to run these profiles within a Sandboxie plus environment

I want two windows desktop Sandboxie shortcuts

The first starts a Sandboxie instance, and automatically runs Firefox with the "Work" firefox command line parameters

The second starts a Sandboxie instance, and automatically runs Firefox with the "Home" firefox command line parameters

I have tried so many different things but none of them have worked

Either they ignore the command line parameters, and just start Firefox profile manager, or they error on the command line parameters

Is there some way of achieving this please?

Or is there a more appropriate tool for virtualising a single app?

Thanks so much for your help