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BE 2012: "backup failed due to corrupt data"

Level 6
Partner Accredited

Hi everyone.  Yesterday I was dealing with a 2008 R2 Hyper-V guest that was blue-screening on boot and rebooting continuously, so I ended up restoring the VHD file for this machine from a previous backup.  That restored file is running fine still, about 20 hours later. 


However last night's full back ran, and gave a job status this morning of failed.  The error says:

(Server: "EX34") (Job: "Full Daily & Weekly to Tape-Full Daily & Weekly ") Full Daily & Weekly to Tape-Full Daily & Weekly -- The job failed with the following error: Corrupt data encountered. See the job log for details.


The job log says this:


WARNING: "EX34.ab\EX34.vhd" is a corrupt file. This file cannot verify.


Then the Verify section of the job log says the same thing. 


So I h ave juset a couple of questions.  First and foremost, even though the status says failed, can I assume from this job log, since the above is the only error, that the rest of the data did back up?  I think yes, but want to hear confirmation if so. 


Second question is just related to the error itself.  The old VHD that was blue-screening would boot normally to Safe Mode and other methods of diagnostic boot, so it just strikes me as strange that BE would somehow determine the file to be corrupt.  Maybe the part of the VHD file, let's say a string of a few hundred bytes got corrupted somehow, and that these bytes represent perhaps a service or something in Windows that if disabled, allows that VHD to boot, but when enabled, BSOD's the machine? 


So really I am just looking fo ran understanding as to how BE was able to know this VHD was corrupt (hash value check? CRC type stuff?).  Interesting that Hyper-V itself doesn't do this pehraps as a background service while VHD's are in use.