Corrupted backup copy

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Re: Corrupted backup copy

Veeam Logoby Gostev » Wed Dec 06, 2017 8:43 am

mkretzer wrote:How should the "auto-healing" of the copy job data work?

https://helpcenter.veeam.com/docs/backu ... tml?ver=95
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Re: Corrupted backup copy

Veeam Logoby mkretzer » Wed Dec 06, 2017 9:00 am

So until the merge of that point is done health check can still find corrupted data?
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Re: Corrupted backup copy

Veeam Logoby Gostev » Wed Dec 06, 2017 9:02 am

Not sure I get the question... but health check verifies the latest restore point regardless of its placement in the backup files.
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Re: Corrupted backup copy

Veeam Logoby mkretzer » Wed Dec 06, 2017 9:55 am

But it always shows the error in the vbk:
06.12.2017 09:54:42 :: Disk wsus_1-flat.vmdk of VM wsus.sw.buhl-data.com is corrupted, possible reason: Storage I/O issue. Corrupted data is located in the following backup files: wsus.vm-781264D2017-12-04T132056.vbk

If there is an incremental point after that (which fixes the "chain" but not the vbk until merge and another health check will run will Veeam still show the corruption in this health check?
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Re: Corrupted backup copy

Veeam Logoby DGrinev » Wed Dec 06, 2017 11:55 am

Hi,

No, since we're reading backup chain starting from the latest increment (which consist of healthy data blocks), the corrupted data blocks are not needed anymore. Thanks!
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Re: Corrupted backup copy

Veeam Logoby mkretzer » Wed Dec 06, 2017 3:31 pm

Then this does not seem to work. In the today copy job a corruption of a smaller VM got detected, the new incement was transfered but validator still shows the corruption. But i really have the feeling that validator checks only the vbk or at least starts with the vbk.

I will try to get a health check running and see if the result differs.
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Re: Corrupted backup copy

Veeam Logoby foggy » Wed Dec 06, 2017 3:39 pm

Veeam Backup Validator is a different thing, unlike health check, it recalculates checksums for the entire backup chain.
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Re: Corrupted backup copy

Veeam Logoby mkretzer » Wed Dec 06, 2017 5:05 pm

So in that case after ther backup with the correction is merged validator should show no error anymore?
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Re: Corrupted backup copy

Veeam Logoby DGrinev » Thu Dec 07, 2017 1:52 pm

After a brief discussion with the QA team, there are no errors expected after the merge of healthy blocks is done. Thanks!
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Re: Corrupted backup copy

Veeam Logoby mkretzer » Thu Dec 07, 2017 4:11 pm

Strange: According to support health check might not really fix these issues:
"About the HealthCheck - we can't be sure that it will be able to heal this particular corruption, and probably BackupCopyJob chain should be recreated. "
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Re: Corrupted backup copy

Veeam Logoby DGrinev » Fri Dec 08, 2017 2:48 pm

Unfortunately, there are several unique conditions leading to inconsistency of the backup chain without ability to fix it by Health Check.
I assume the support team found those conditions during the investigation and report you the negative results. Thanks!
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Re: Corrupted backup copy

Veeam Logoby mkretzer » Fri Dec 08, 2017 7:22 pm

Ok that leads to the question - what can health check fix and what not? From what i understand there was just one backup block which was too short after decompression. Why should this not be fixable?
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Re: Corrupted backup copy

Veeam Logoby DGrinev » Sat Dec 09, 2017 4:36 pm

That's the good question, I will try to find out next week and give you an example. Thanks!
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Re: Corrupted backup copy

Veeam Logoby Gostev » Mon Dec 11, 2017 4:23 pm 1 person likes this post

The answer to this question is in the name of the feature, which is "storage-level corruption guard". And it does just that, nothing more and nothing less: detects silent data corruptions in your backup storage, and attempts to make the latest restore point restorable by copying all corrupted blocks over again from the source.
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Re: Corrupted backup copy

Veeam Logoby mkretzer » Mon Dec 11, 2017 7:45 pm

And it works :-)
Last restore point shows clean health even without AF.
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