Hello
If the Write checksums to media option is selected as a default backup option, checksums are calculated for each data stream written to tape, and then written in a separate stream immediately following the data stream.
During verify job operation, Backup Exec reads the data stream and re-calculates the check sums and compares it with what is written in the media.
Backup Exec does not compare the files on the tape with the files on the hard disk. Instead, it performs a CRC (Cyclic Redundancy Check) verification of the data on the tape. A CRC performs a mathematical calculation on a stream of data and returns a number that represents the content and organization of that data and uniquely identifies this data stream .This CRC verification ensures the data was stored correctly and can be re-read.
This error could occur if Backup Exec incorrectly read the check sum and was not able to verify the data.
This error occurs due to hardware/media related issues .The following list contains the most common reasons for this error and potential ways to resolve the problem
1) Media related problems: { bad media}
a) Perform an "Erase" operation on the media.
b) Use a new media.
2) Tape drive related problems:
Following trouble shooting steps can be tried :
a) Clean the tape drive multiple times.
b) Apply the latest drivers and firmware for the device.
c) Uninstall and re-install the VERITAS device drivers for the tape drive by following the steps below.
3) Bad SCSI connection
Hope this helps you.
Regards
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