Backup of 4K Native Disks Fails

Product version: 11.2

Last modified: 26 March 2026

Problem

Backup jobs for physical machines or virtual machines fail or not complete successfully when the source system uses 4K native (4Kn) disk sectors.

Even in scenarios where backup data exists, granular and instant recovery capabilities—including FLR, OLR, UOR, and FlashBoot—are not supported.

Background

4Kn disks use 4096-byte physical sectors instead of the traditional 512-byte sectors.

Support for 4Kn disks in NAKIVO Backup & Replication is limited. This limitation applies to workloads using 4Kn (4K native) disks, whether physical or virtual, where the disk sector size is exposed as 4Kn.

Solution

To proceed, consider one of the following approaches:

• Use supported disk formats. Use disks with:

  • 512-byte native (512n), or

  • 512-byte emulation (512e) sector size

• Modify disk configuration. Where feasible, reconfigure or replace disks to use a supported sector format.

• Use full recovery as a workaround. If backups of 4Kn disks complete successfully, only full machine recovery can be used. Granular and instant recovery options are not available.