# WARNING Data error (cyclic redundancy check) occurred inside byte range

During the backup of a Disk Image Protected Item, you may receive a warning similar to:

`WARNING: read \Device\HarddiskVolumeShadowCopy: Data error (cyclic redundancy check). occurred inside byte range xxxxxx - xxxxxx. Skipping this range, some files may be unrecoverable.`

This error indicates a hardware failure with the hard drive or a component between it and the operating system. The Disk Image backup should be saved, but but with these byte ranges empty.

If you have recently replaced your hard drive, cloning the the old hard drive to the replacement, it is possible that some of the cloned data was corrupt on the old hard drive and has been replicated to the replacement. This issue can occur with 3rd party disk cloning tools where corrupt files from bad sectors on the disk will be replicated to the replacement hardware.

If you are confident that the hard drive and hardware (disk controller, SATA cables, etc.) in the system is in good condition, you can try performing an on-boot chkdsk

#### chkdsk /B /X

* Right-click the “Start menu” and select “Windows PowerShell (Admin).” In the User Account Control (UAC) window, select “Yes” to give it permission to launch the Windows Command Processor and make changes. Type “`chkdsk c: /x /r`” without the quotes to scan it for errors, and repair it.<br>
* Try replacing the SATA cables, and plugging the drive into another SATA port
* Confirm that the VMDK image is available for restore.
* Perform a test restore of the VMDK image, run your VMDK Disk Image in an application like Virtual Box to confirm you have a good backup.

***

[eazyBackup](https://eazybackup.com)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.eazybackup.com/troubleshooting/warning-data-error-cyclic-redundancy-check-occurred-inside-byte-range.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.