Proxmox Backup Failure Caused by Zeroinit Filter

Product version: 11.0

Last modified: 08 July 2025

Problem

In a Proxmox environment, a backup or replication job may fail with the following error:

There is a disk containing the "zeroinit" filter. This may occur after live storage migration.
Please hard reboot/stop/shutdown the VM on the Proxmox host (No Guest OS reboot) to remove the zeroinit filter.

Background

The source virtual disk is configured using the zeroinit block driver, which is intended to simulate zero-filled reads for unallocated areas. As a result, any overlay or snapshot derived from this disk inherits the zeroinit layer. This introduces a read-only constraint that prevents operations such as backup, replication, or other write-related processes from functioning correctly.

Note

Disks using the zeroinit driver are not supported for backup, replication, or snapshot operations. NAKIVO Backup & Replication automatically detects the presence of a zeroinit block driver, and if found, the Transporter fails the job.

Solution

To resolve this limitation, hard reboot/stop/shutdown the VM on the Proxmox host. After the VM reboots, the zeroinit filter is removed.

Important

Reboot the VM with host-level controls, not from the Guest OS.