Virtualization· 33 posts
Automate KVM Provisioning With Bash and virsh
Validate a declarative guest inventory before changes; Provision multiple predictable guests; Rerun with no duplicate resources or identity drift; Run scoped cleanup against only the episode prefix.
Build a Three-Node KVM HA Lab
Provision kvm-ha01, kvm-ha02, and kvm-ha03 with nested KVM; Create consistent names, time, networks, and storage paths; Form Corosync and Pacemaker membership; Prove three votes, quorum, and clean libvirt readiness on every node.
Design a Highly Available KVM Cluster
Map three-host quorum and every traffic path; Define fencing authority and failure domains; Set recovery objectives and capacity headroom; Fail the design review when storage or fencing is single-path and undocumented.
Configure KVM Fencing and Prove Split-Brain Protection
Configure outer-hypervisor power control for each nested HA node; Isolate the active node; Prove fencing completes before guest restart; Test quorum loss and show that unsafe restart is refused.
Test KVM Host Failure and Automatic VM Recovery
Run an external one-second application probe; Abruptly fail the active KVM host; Measure detection, fencing, restart, and service recovery; Validate data, rejoin the host, and clear only understood failures.
Build Isolated KVM Lab Networks
Define application and database-only libvirt networks; Assign deterministic DHCP identities where required; Prove allowed east-west traffic; Prove the database segment has no unintended WAN route.
Give a KVM VM Direct LAN Access With a Linux Bridge
Inventory the existing physical bridge without changing it; Attach a disposable guest interface to br0; Validate a LAN address and two-way reachability; Remove the interface without interrupting host management.
Perform a Live KVM Migration and Measure the Interruption
Start an external one-second service probe; Migrate a running guest with the selected storage topology; Measure the last-success to first-success gap; Prove persistent ownership and disk paths on the destination.
Understand qcow2, Raw Disks, and KVM Storage Pools
Create equal virtual-capacity qcow2 and raw volumes; Compare apparent size and allocated space; Convert in both directions and verify data hashes; Measure a bounded I/O comparison and explain its limits.
Add a KVM Virtual Machine to Pacemaker
Define one cluster-owned guest consistently; Configure start, stop, monitor, and placement behavior; Move the guest cleanly between nodes; Prove only one node owns the running domain and disk at a time.
Monitor and Troubleshoot KVM Performance
Create bounded CPU, disk, and network symptoms one at a time; Correlate libvirt counters with host and guest evidence; Identify the actual bottleneck before changing configuration; Remove the load and prove counters and latency recover.
Migrate a KVM VM to Another Host
Preflight CPU, networks, storage paths, and destination capacity; Shut down and transfer XML plus all writable disks; Start only the destination copy; Verify identity, disks, networks, data, and a tested rollback path.
Operate and Maintain a KVM HA Cluster
Patch and reboot one node through standby or maintenance mode; Return workloads and verify placement intentionally; Replace or rebuild one nested host; Review quorum, resource, storage, fencing, and failure history before final sign-off.
Recover a Broken KVM Virtual Machine
Reproduce a safe domain start failure; Identify the first causal error across virsh, journal, and QEMU logs; Repair only the bad definition or path; Start the original guest and verify both disks and networks.
Remove the KVM HA Storage Single Point of Failure
Replace the single storage path with the selected redundant design; Prove identical safe access from every compute node; Fail one storage path or node while the workload runs; Validate data integrity and document remaining correlated failures.
Repair a KVM VM That Will Not Boot
Create a reversible guest boot failure; Attach rescue media or mount an overlay-backed disk offline; Repair the filesystem or configuration; Boot normally and validate the repaired service.
Build Repeatable KVM VMs With cloud-init
Build a reusable base without embedded secrets; Generate unique NoCloud identity and network data; Create two guests from independent overlays; Prove unique UUIDs, MACs, hostnames, machine IDs, SSH keys, and addresses.
Create an Ubuntu VM with KVM, virt-install, and cloud-init (2026)
Create a reusable Ubuntu 24.04 KVM guest from a cloud image with virt-install, cloud-init, private networking, QEMU guest agent, SSH, and a serial console.
Install KVM on Ubuntu: Complete libvirt Host Setup (2026)
Install KVM, QEMU, libvirt, virsh, and virt-install on Ubuntu, then configure permissions, private networking, and validate the finished virtualization host.
KVM Networking: Custom NAT Network with Static DHCP
Create a persistent libvirt NAT network, reserve a predictable DHCP address, attach a second virtio NIC, configure Netplan, and control route priority.
KVM Storage Pools and Volumes: Attach and Expand a Disk
Create a libvirt storage pool and qcow2 volume, attach it to a running KVM guest, format it, then expand the active disk and ext4 filesystem safely.
KVM Virtualization Series: Build and Manage a Linux Hypervisor Lab
Follow the complete InventiveHQ KVM series from host installation through virtual machines, storage, networking, backups, performance tuning, GPU passthrough, and migration.
Virsh Commands: Complete KVM & libvirt Cheat Sheet (2026)
Use virsh to list, inspect, start, stop, configure, and safely remove KVM virtual machines. Includes tested local and remote libvirt commands.
Virtualization History: 1960s Mainframes to Cloud
Discover how virtualization evolved from IBM mainframes in the 1960s through VMware, Docker containers, Kubernetes, and serverless computing to today's cloud infrastructure.
Best Motherboard & CPU for Virtualization
The exact CPU and motherboard features that matter for VMs — VT-x/AMD-V, VT-d/AMD-Vi (IOMMU), core counts, ECC, memory channels, PCIe lanes, and NICs — ranked by why each one changes VM performance and stability.
KVM Installation Guide | Linux Virtualization Setup
Install and verify KVM on Fedora, RHEL, CentOS Stream, Rocky, or AlmaLinux with current dnf commands: check virtualization support, install @virtualization, enable libvirtd, run virt-host-validate, and build your first VM.
Server Virtualization Guide | Complete Introduction
Discover how server virtualization enhances efficiency, reduces costs, and scales with VMware, Hyper-V, and open-source platforms.
Automatically Deploy Puppet Agent on VMWare Templates
Learn how to auto-deploy Puppet Agent on VMware templates using simple run once commands for streamlined configuration management.
Benefits of Using Virtualization for Disaster Recovery
Transform your disaster recovery strategy with virtualization. Reduce downtime, eliminate hardware dependencies, and ensure business continuity when disruptions strike.
How to Fix Invalid VMs in vCenter: Step-by-Step Guide
Fix invalid VMs in vCenter fast: step-by-step commands for VM reload, re-registration, datastore recovery, and prevention best practices for VMware admins.
Vagrant with VMware vCenter Integration
Set up Vagrant with VMware vCenter to provision and manage virtual machines effortlessly
Software Portability Guide | Cross-Platform Success
Master published applications, virtualization, and containerization to achieve seamless cross-platform deployment and optimal resource efficiency
VirtualBox Ubuntu Setup | Complete Installation Guide
Install VirtualBox and create your first Ubuntu virtual machine with this comprehensive step-by-step tutorial