It seems you're encountering an issue with the CloudLinux VM hanging when the qemu-guest-agent calls fsfreeze on Proxmox. This can happen due to various reasons, including compatibility issues or misconfigurations. Here are steps you can take to address this:

1. Check qemu-guest-agent Version:

   • Ensure you're using a compatible version of qemu-guest-agent that works well with CloudLinux and Proxmox.

2. Verify CloudLinux Version:

   • Make sure you're using a CloudLinux version that is known to be compatible with the version of Proxmox you're running.

3. Update or Reinstall qemu-guest-agent:

   • Try updating or reinstalling qemu-guest-agent on your CloudLinux VM.

4. Check for Compatibility Issues:

   • Look for any known compatibility issues between qemu-guest-agent, CloudLinux, and Proxmox. This information might be available in documentation or community forums.

5. Verify fsfreeze Support:

   • Confirm that the file system you're using on CloudLinux supports fsfreeze. Not all file systems do, and this could be a potential source of the issue.

6. Review Proxmox Settings:

   • Check if there are any specific settings within Proxmox that might conflict with qemu-guest-agent. This could include settings related to virtual machine snapshots or backups.

7. Check Logs for Errors:

   • Review system logs on both CloudLinux and Proxmox for any error messages or warnings related to qemu-guest-agent file system freezing.

8. Test fsfreeze Manually:

   • Test the fsfreeze command manually on CloudLinux to see if it's working as expected. This will help isolate whether the issue is specific to qemu-guest-agent.

9. Consult Proxmox and CloudLinux Communities:

   • Search forums and community resources specific to Proxmox and CloudLinux for any reported issues or solutions related to qemu-guest-agent and fsfreeze.

10. Contact Support:

    • If the issue persists, consider reaching out to Proxmox and CloudLinux support. They may have specific recommendations or troubleshooting steps for your environment.

11. Consider Alternative Backup Methods:

    • If fsfreeze continues to cause issues, consider using alternative methods for VM backups, such as snapshots or backup solutions that don't rely on fsfreeze.

Remember to back up your data and configurations before making any significant changes to your virtual machines or infrastructure.