How does cyclic redundancy check (CRC) work?

How does cyclic redundancy check (CRC) work?

How does CRC (Cyclic Redundancy Check) work? Say you have a backup application writing data to a tape device and the process writing data to tape reports CRC error. At time of this error the device driver reports event Id 7. Does the CRC check happen in the drive itself?

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Most modern tape drives do support CRC within their drive so yes, CRC checking is probably happening in the drive in your case.

However, some backup software also supports CRC within their software. So, telling you all of the cases where CRC is happening in your case is difficult to say. Usually if your tape drive is performing the CRC check, you will simply get a write error if it fails.

I wouldn't think that your backup software would actually report it as a CRC failure. This leads me to believe that this is your backup software that is doing the CRC check and failing as well.

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This was first published in April 2003