Recover protected systems with 4K AF drives - x360Recover BDR

Written By Tami Sutcliffe (Super Administrator)

Updated at March 8th, 2023

Many new computer systems are beginning to ship with Advanced Format (4K) hard drives. These devices have a native low level block size of 4096 (4K) rather than the 512 bytes used by standard drives. 

Support for protected systems with Advanced Format Disks (Native 4K block size.):

Backup and recovery of protected systems using 4K drives is supported with 

  • x360Recover agent version 2.25+ and 
  • x360Recover appliance/vault version 10.8.0+

Recovery actions available for 4K drives include Mount, iSCSI, and Bare Metal Recovery. 

  • Export of 4K disks to virtual disk image is not yet supported.

Important:  You can only recover "like-for-like" disks when using Bare Metal Recovery.  If your original disk is 512 (even 512e!) you cannot recover to a 4K disk (or vice versa). This is because the physical block data cannot be converted during an imaging process

  • Only RAW (KVM) and VHDX (Hyper-V) virtual disk formats support 4K disk images.  This essentially limits recovery of physical servers using 4K drives to either KVM or Hyper-V virtual host environments 

Recovery actions available



Mounting snapshots of protected systems with 4K disks for performing file and folder recovery is supported by any version of x360Recover.



Exporting a protected system via iSCSI works normally.  Storage volumes may be mounted by any remote system that natively supports 4K disks and the data will be presented correctly.


Virtualization (appliances and legacy vaults)

Limited support for virtualization of systems containing 4K drives is available in x360Recover 10.1.0 and newer.

  • The underlying KVM hypervisor requires the use of VirtIO drivers and disks to create virtual 4K volumes. 
  • Because Windows does not natively support VirtIO, drivers must be injected into the virtual machine image before Windows is able to boot. 
  • Virtualization of protected systems in test mode, bootvm checks, and AutoVerify are not currently supported.  
  • Virtualization in live mode is supported with manual injection of the required drivers.

For detailed instructions on virtualizing a protected system with 4K drives, see this KB Article.


Virtualization (Axcient Scale-Out Cloud Vaults)

Near-instant virtualization of protected systems with 4K drives is available for partners with Scale-Out Cloud vaults within the Axcient Continuity Cloud.

For detailed instructions on virtualizing a protected system on a Scale-Out Cloud vault, see this KB Article



x360Recover’s native virtual disk export utility currently does not support recovery of data from protected systems using Advanced Format (4K block-size) hard drives. 

This article will provide a workaround for creating a 4K formatted VHDX virtual disk file.  You will need a working Windows machine with Hyper-V services installed.  At present, Hyper-V is the only Hypervisor with simple support for virtualizing protected systems with native 4K disk volumes.  (VMware does not support guest operating systems with 4K virtual disk volumes.)

For detailed instructions on exporting a Protected System with 4K drives, see this KB Article


Bare Metal Recovery

The x360Recover Bare Metal Recovery (BMR) wizard leverages iSCSI to expose the protected system disk volumes. Recovery to physical hardware via BMR is supported. 

The Bare Metal Recovery process works by cloning the exported iSCSI volumes to physical volumes, so the underlying hardware must match. 

There is no translation between native block formats and you cannot recover backups of standard 512 byte block drives to 4K drives or vice versa.


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