cloud-localds seed.iso user-data Attach ISO to VM. | Area | Recommendation | |------|----------------| | Disk I/O | Use virtio-scsi + discard (TRIM support) | | Memory | Install qemu-guest-agent for ballooning | | Time sync | systemctl enable --now chrony | | Kernel | Use linux-image-virtual (lighter) | | SSH | Disable password auth, use SSH keys | | Firewall | ufw default deny incoming && ufw enable | 6. Converting Between Formats Convert a .vmdk (VMware) to .qcow2 (KVM):
#cloud-config users: - name: admin sudo: ALL=(ALL) NOPASSWD:ALL ssh_authorized_keys: - ssh-rsa AAAAB3... packages: - docker.io - htop Generate ISO: vm image ubuntu
22.04 (Jammy), 24.04 (Noble). Non-LTS releases (e.g., 24.10) are also available for testing. 3. Common Hypervisors and Image Formats | Hypervisor | Preferred Format | Ubuntu Image Command / Step | |------------|----------------|-----------------------------| | KVM/QEMU | .qcow2 | qemu-img convert -O qcow2 ubuntu.img disk.qcow2 | | VirtualBox | .vdi or .vmdk | VBoxManage import ubuntu.ova | | VMware ESXi/Workstation | .vmdk | Direct attach or OVF import | | Hyper-V | .vhdx | New-VM -VHDPath .\ubuntu.vhdx | | Xen/Proxmox | .qcow2 | qm importdisk <vmid> ubuntu.qcow2 <storage> | 4. Creating a Custom Ubuntu VM Image (Step-by-Step) 4.1 Base Image Download wget https://cloud-images.ubuntu.com/noble/current/noble-server-cloudimg-amd64.img 4.2 Resize Disk (Default ~2–5 GB) qemu-img resize noble-server-cloudimg-amd64.img +20G 4.3 Launch VM (KVM example) qemu-system-x86_64 -m 4096 -smp 2 -drive file=noble-server-cloudimg-amd64.img,format=qcow2 -net user,hostfwd=tcp::2222-:22 -net nic 4.4 Customize (cloud-init) Create user-data : cloud-localds seed
Abstract Ubuntu, a dominant Linux distribution, is widely deployed as a virtual machine (VM) image due to its stability, security updates, and cloud integration. This paper examines the structure, acquisition, configuration, and optimization of Ubuntu VM images. It covers official sources (Ubuntu Cloud Images, Vagrant boxes), hypervisor compatibility (VMware, VirtualBox, KVM, Hyper-V), and key practices for resource management, guest additions, and system hardening. 1. Introduction Virtual machine images are pre-configured disk templates containing an operating system and optional software. Ubuntu provides official, minimal, production-ready VM images for x86_64 and ARM64 architectures. These images reduce deployment time from hours (bare-metal install) to minutes. 2. Sources of Official Ubuntu VM Images | Source | Format | Use Case | |--------|--------|----------| | Ubuntu Cloud Images | .qcow2 , .raw , .vmdk , .vhdx | KVM, OpenStack, Proxmox, WSL2 | | Vagrant Cloud | Vagrant boxes (VirtualBox, libvirt, Hyper-V) | Development environments | | OSBoxes (community) | .vdi , .vmdk | VirtualBox/VMware learning | | Microsoft Hyper-V Gallery | .vhdx | Windows Hyper-V | packages: - docker
qemu-img convert -f vmdk ubuntu.vmdk -O qcow2 ubuntu.qcow2 Convert .vdi (VirtualBox) to .raw :
