Debian set up (using SpiralLinux as installer)

 https://github.com/SpiralLinux/SpiralLinux-project (for Btrfs/Snapper set up)

 

Disk creation:  

1. Select Manual Partitioning in Calamares
2. Create the partition table (if starting fresh):
◦  Select your disk (e.g., /dev/vda)
◦  Create a new GPT partition table
3. Create EFI System Partition:
◦  Size: 1024 MiB (1 GB as requested, instead of 300M)
◦  File system: FAT32
◦  Mount point: /boot/efi
◦  Flags: Set the boot and esp flags
4. Create Root Partition:
◦  Size: Remaining space (~79 GB)
◦  File system: Btrfs (since your setup shows multiple subvolumes)
◦  Mount point: /
◦  No flags needed
5. Configure Btrfs Subvolumes (if Calamares supports it):
   After creating the Btrfs partition, you'll need to set up subvolumes for:
•  @ → /
•  @home → /home
•  @root → /root
•  @tmp → /tmp
•  @log → /var/log
•  @snapshots → /.snapshots 

Install packages:

sudo apt install -y $(cat packages.txt)

 

Install Flatpak & Homebrew: 

./flatpakAndBrew.sh

 

Install Flatpaks: 

sudo flatpak install -y $(cat flatpaks.txt)

 

Install Cosmic Desktop (from Fedora COPR): https://github.com/davidecavestro/cosmic-debian-sh-installer.git     

For VM, I found I needed to install libdisplay-info2 for cosmic-comp (and you need to enable  3D acceleration (first set listen type in Display Spice to "None" and check OpenGL; then enable 3d Acceleration in "Video Virtio")

 

Install complete QEMU/KVM stack with virt-manager on Debian 13.

Step 1: Verify CPU Virtualization Support

First, check if your CPU supports hardware virtualization:

egrep -c '(vmx|svm)' /proc/cpuinfo

If this returns a number greater than 0, your CPU supports virtualization. You can also check more details:

lscpu | grep Virtualization

Step 2: Install QEMU/KVM and Related Packages

Install the complete virtualization stack:

sudo apt update
sudo apt install qemu-system qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils virt-manager

Package breakdown:

• qemu-system and qemu-kvm - The hypervisor and emulator
• libvirt-daemon-system - Management daemon for virtualization
• libvirt-clients - Client tools for managing VMs
• bridge-utils - Network bridging utilities
• virt-manager - Graphical VM management tool

Step 3: Add Your User to Required Groups

Add your user to the libvirt and kvm groups:

sudo usermod -aG libvirt $(whoami)
sudo usermod -aG kvm $(whoami)

Log out and log back in for group changes to take effect, or run:

newgrp libvirt

Step 4: Enable and Start libvirtd Service

sudo systemctl enable libvirtd
sudo systemctl start libvirtd

Verify it's running:

sudo systemctl status libvirtd

Step 5: Verify KVM Installation

Check if KVM modules are loaded:

lsmod | grep kvm

You should see either kvm_intel or kvm_amd depending on your CPU.

Verify libvirt connectivity:

virsh list --all

Step 6: Configure Default Network (if needed)

The default network should start automatically. If not:

sudo virsh net-start default
sudo virsh net-autostart default

Step 7: Launch virt-manager

You can now launch virt-manager from your application menu or run:

virt-manager

Optional: Install Additional Useful Tools

sudo apt install virt-viewer guestfs-tools

• virt-viewer - Lightweight VM display client
• guestfs-tools - Tools for accessing and modifying VM disk images

Troubleshooting

If you encounter permission issues, ensure:

1. Your user is in the correct groups (check with groups)
2. /var/run/libvirt/libvirt-sock has proper permissions
3. The libvirtd service is running

That's it! You now have a fully functional QEMU/KVM virtualization environment with virt-manager on Debian 13.