Mirror Backup Corrupted Destination Files

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bokarinho
Posts: 1
Joined: Mon Mar 22, 2021 10:53 am

Mirror Backup Corrupted Destination Files

Post by bokarinho »

Hello,
Using FBackup Version 9 Build 199 with backup type:mirror backup, i came accross a situation that destination files (*.docx) become corrupted.
I will try to describe the case:
In source there is a document file (A.docx) that has null content (is empty).
In destination there is a document file with the same name (A.docx) that has content.

When running the mirror backup, the application takes into consideration the difference between the source and destination files and prompts the user to continue or stop/abort the mirror backup.
See log below:
"[22/3/2021 12:12:58 μμ] \\BACKUP\user\D\Personal\IQBOARDS.jpg OK
[22/3/2021 12:12:58 μμ] Warning: Size of file "\\BACKUP\user\D\Personal\Αναφορά Παραπόνου PELMATOGRAMIMA-ELITE.docx" in destination (13598) is different than the size stored in catalog (13540)
Test finished in 0 second(s) at 22/3/2021 12:12:58 μμ, 2 file(s) and 0 folder(s) tested, 0 error(s) and 1 warning(s) found"

When choosing no (choice that equals to aborting the backup process) the destination file (A.docx) becomes corrupted as when i try to open the file with MS Word 2010 it mentions that the file is corrupted and as a next step the recovery dialog is shown. Finally when i choose to recover the file, instead of having its initial content, it has null content that comes from the source file.

So to sum up:
  • 1. Canceling the mirror backup leaves corrupted files in destination.
    2. Canceling the mirror backup does not stop the copy from source to destination process.
Can you check it?

Adrian (Softland)
Posts: 1764
Joined: Thu May 23, 2013 7:57 am

Re: Mirror Backup Corrupted Destination Files

Post by Adrian (Softland) »

Hi,

The mirror backup is not working that way.
When running the backup, if a file already exists in destination, it will be overwritten with the new source file version. You are not asked if you want to overwrite each file in destination.

In your case, when you ran the backup, it seems that "Αναφορά Παραπόνου PELMATOGRAMIMA-ELITE.docx" was in use by another application. In such a case, FBackup asks Windows for the Shadow Copy of that file.
As the file was modified during the backup, the size difference exists.

During the "test after backup" phase FBackup will inform the size of the file backed up in destination is different than the size stored in catalog (which is read at the beginning of the backup)

svanetempest
Posts: 17
Joined: Sun Jan 07, 2018 3:36 pm

Re: Mirror Backup Corrupted Destination Files

Post by svanetempest »

Interesting comment.
I had an XLS file (closed since the day before) and that copied in a mirror backup with a warning on a size difference - and excel had to repair the file.
The same file had a mirror backup an hour later to a separate NAS box with the same discrepancy in the catalog.
Not sure how a simple mirror copy/replace can corrupt a file.
File can be copied from explorer with no problems.
This fails only part of the time - other times it is all ok (the same file being updated)
The catalog was migrated from v8
Is there any way to rebuild the catalog without a complete new job being created? I have noticed that the log file now contains all the entries under 'excluded' which I may have simply moved to a different directory rather than specifically excluded.

svanetempest
Posts: 17
Joined: Sun Jan 07, 2018 3:36 pm

Re: Mirror Backup Corrupted Destination Files

Post by svanetempest »

Same again today with a simple text file.
Warning message was..
[29/03/2021 12:40:38] Warning: Size of file "\\xxxx\Books Needed in progress.txt" in destination (4088) is different than the size stored in catalog (4038)
The catalogue was correct - how on earth can a copied file be bigger?
I never had these sort of issues with V8.

Adrian (Softland)
Posts: 1764
Joined: Thu May 23, 2013 7:57 am

Re: Mirror Backup Corrupted Destination Files

Post by Adrian (Softland) »

Hi,

We found the problem and we will fix it in the next build.

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