ProxCLMC

Table of Contents

• ProxCLMC
  • General
  • Why ProxCLMC?
  • How it works
  • Example Output
  • Installation
    • Requirements / Dependencies
    • Install: Via Debian Repository
    • Install: Via .deb Package
    • Usage (Run proxclmc)
    • Options
  • Building from Source
  • License
  • Author

General

ProxCLMC (Prox CPU Live Migration Checker) is a lightweight tool to determine the maximum CPU compatibility level that is supported across all nodes in a Proxmox VE cluster. It remotely inspects each cluster node via SSH, analyzes CPU capabilities, and calculates the lowest common x86-64 CPU baseline to ensure safe live migration and predictable VM behavior. By default, proxclmc runs on any Proxmox VE node, inspects the local corosync.conf and parses all nodes within a cluster to detect the maximum of supported CPU compatibility level.

Why ProxCLMC?

In mixed-hardware Proxmox clusters, CPU feature mismatches are a common source of:

• Failed live migrations
• Unstable VM behavior
• Severe performance degradation (especially for Windows VMs when using the host CPU type)

ProxCLMC provides a deterministic, cluster-wide answer to the question:

Which CPU type can I safely use for all VMs in this cluster?

How it works

• Parses cluster nodes directly from corosync.conf
• Connects to each node via SSH
• Reads /proc/cpuinfo remotely
• Extracts CPU flags
• Maps flags to x86-64 CPU baselines
• Calculates the lowest common CPU type across all nodes
• Fully compatible with Proxmox / QEMU CPU models:
  • x86-64-v1
  • x86-64-v2-AES
  • x86-64-v3
  • x86-64-v4

This brings in the CPU compatibility validation to Proxmox VE based clusters, which might already be known from other virtualiaztion solutions (e.g., VMware EVC).

Example Output

All available nodes in a Proxmox Cluster will be listed by their supported CPU model. Afterwards, the maximum usable CPU type for the cluster will be printed that can be used for VMs to ensure safe live-migrations:

test-pmx01 | 10.10.10.21 | x86-64-v3
test-pmx02 | 10.10.10.22 | x86-64-v3

Cluster CPU type: x86-64-v3

Installation

Requirements / Dependencies

• Proxmox VE Cluster
• SSH Authentication between all PVE nodes

Install: Via Debian Repository

The packaged version for Debian based systems (including Proxmox) are shipped within @gyptazy's Debian repository (which also serves the ProxLB project). The repository can simply be added by running the following commands and installing the Debian package proxclmc:

echo "deb https://repo.gyptazy.com/stable /" > /etc/apt/sources.list.d/proxlb.list
wget -O /etc/apt/trusted.gpg.d/proxlb.asc https://repo.gyptazy.com/repository.gpg
apt-get update && apt-get -y install proxclmc

Install: Via .deb Package

As an alternative, you can also simply download the Debian package from @gyptazy's CDN and install it afterwards:

wget https://cdn.gyptazy.com/debian/proxclmc/proxclmc_1.0.0_amd64.deb
dpkg -i proxclmc_1.0.0_amd64.deb

Usage (Run proxclmc)

After installing the Debian package via the Debian repository or from the gyptazy CDN, you can simply run the command:

proxclmc

Options

The following cli options are available:

Short	Long	Argument	Default	Description
-s	--ssh-file	<SSH_FILE>	/root/.ssh/id_rsa	SSH private key to use
	--version			Print version information
-v	--verbose			Enable verbose output
-h	--help			Print help

Building from Source

Building ProxCLMC is easy and can be done by installing the following requirements for Rust/Cargo:

apt install -y cargo rustc libssh2-1-dev pkg-config

Afterwards, you can build the project from source:

cargo build --release

The resulting binary will be located at:

• target/release/ProxCLMC

License

This project is licensed under the GNU General Public License v3.0 or later. SPDX-License-Identifier: GPL-3.0-or-later

Author

• Florian Paul Azim Hoberg @gyptazy (https://gyptazy.com)