Pavmkvm801qcow2 — New
While there is no formal academic paper with the specific title " pavmkvm801qcow2
cluster_size=dynamic: Enables the new DCM 2.0 feature.pavm_version=801_new: Explicitly invokes the optimized code path.lazy_refcounts=on: Recommended for better write performance with the new async discard.
- Backward Compatibility: Images created with the "new" feature flag cannot be opened by QEMU versions older than 8.1.0. They will throw a "Unknown extension" error.
- Memory Overhead: The dynamic cluster mapping requires approximately 8MB of additional RAM per active VM to manage the red-black delta trees. For memory-constrained edge nodes, you may revert to the fixed cluster variant.
- Backup Tools: Ensure your backup solution (e.g.,
virt-backup, Proxmox Backup Server) supports the new asynchronous discard metadata. As of this writing,libguestfsv1.52+ fully supports it; older versions may report false corruption errors.
Creating a new QCOW2 image (standard way):
qemu-img create -f qcow2 pavmkvm801.qcow2 20G
Prerequisites
- Host OS: Any Linux distribution with KVM support (Proxmox VE, Ubuntu 22.04+, RHEL 9+).
- Packages:
qemu-kvm,libvirt-daemon-system,virt-manager(optional),qemu-utils. - Storage: At least 20 GB free on your target directory.
Resize the Virtual Disk:qemu-img resize pavmkvm801.qcow2 +10G pavmkvm801qcow2 new