How to Fix: Data error (cyclic redundancy check)

You may see the error

Data error (cyclic redundancy check)


in the Windows Event Viewer or in the logs of your backup tool followed by a failure.

When these errors refer to a disk drive, usually data errors and cyclic redundancy check errors are due to serious disk defects.

It’s is strongly recommended to copy your files immediately to another disk!

In over 99% of all cases reported to us, the error “Data error (cyclic redundancy check)” was due to bad sectors on the disk.


How to Confirm a Disk Issue

You can run a check disk command to make Windows bypass those sectors; however, usually disks fail completely within a short period once you encounter a bad sector.

Copying your files out of the defected drive should hence be your highest priority. After that, you could run a the chkdsk command to inspect the drive:

chkdsk X: /b

Where X: is the drive letter and b is the option to reevaluate every single cluster on disk, see

Note that:

A. this test takes many hours to complete, depending on hard drive capacity and speed. It could take half a day or more and it could damage more files.

B. this test is very stressful for a drive and may very well destroy the drive completely. It is not unusual for hard drives to fail completely when put under high load.


Other Causes

In rare cases the error “Data error (cyclic redundancy check)” is actually a driver issue. However, this driver issue would appear immediately after installing the drive or RAID controller, not weeks or years later.

Another thing to remember is that even brand new drives ship out defected. We hear many times from our customers how brand new servers arrived with hard drive defects.


Data Loss Prevention Strategies

The best strategy is to create backups often and religiously. Ideally using an automated backup tool, such as BackupChain. Try it today for free and protect your data from being lost due to data errors and other hard drive defects.
Backup software is far more than just a copy tool. You can protect against data loss by backing up a server to the cloud or to a remote backup server. While online server backup is a great strategy, it’s best to have several local and network based (NAS) backups as well, for speedy recovery.
Many businesses today use virtual machines. Using BackupChain you can backup VMs while running using its Hyper-V backup function. Moreover, BackupChain supports other hypervisors as well, such as VMware backup and VirtualBox backup.

Backup Software Overview

The Best Backup Software in 2021
Download BackupChain®

BackupChain is the all-in-one server backup software for:
Server Backup
Disk Image Backup
Drive Cloning and Disk Copy
VirtualBox Backup
VMware Backup
FTP Backup
Cloud Backup
File Server Backup
Virtual Machine Backup
Server Backup Solution

Hyper-V Backup

  • 18 Hyper-V Tips & Strategies You Need to Know
  • How to Back up Windows 10 Hyper-V VMs
  • Hyper-V Backup