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Cannot restore deduplicated files

Posted: Fri May 12, 2017 12:56 pm
by lucwuyts
Since i activated deduplication on a data volume (in a hyper-v host), i cannot restore files.
I think only deduplicated files cannot restore

Error message is like this for these files:

C:\ProgramData\BackupAssist v9\temp\1jn1em1g\OnlineKAT03\KAT03_FileServerData\Volume1\NetwerkData\(4602) GEBRUIKERS - IOP\Ait Daoud Mouad\IOP - Ait Douad Mouad\IOP ARCHIEF - Ait Douad Mouad\IOP na ronde tafel - Mouad Ait Douad.pdf - The file cannot be accessed by the system

Restoring the same data from a backup from before deduplication was activated works perfectly.

Re: Cannot restore deduplicated files

Posted: Fri May 12, 2017 2:56 pm
by Stuart
Hi Luc,

Thanks for posting on our forum. Can you provide some more detail of your actual environment so that we know a bit about your configuration?

- BackupAssist Version (e.g. V9.5.4).
- Type of backup being performed (e.g. System Protection).
- Operating system of machine BackupAssist is installed on.
- Hardware being used as your backup destination.

Re: Cannot restore deduplicated files

Posted: Fri May 12, 2017 3:19 pm
by lucwuyts
Hi Stuart,

BackupAssist version 9.5.4
HOST OS: Windows Server 2012 R2
There are 3 hyper-v machines included in the backup.
Backup type = System Protection to a local disk, and to an other Networked server at an other location. (also system protection backup)

The backup i need to restore from was marked as OK by BackupAssist.
(but i did not select backup verification from hyper-v guests)

The file restore I have a problem with is from files on a hyper-v machine running windows 2012 R2
And this is from a volume where Deduplication is active.
I started this deduplication on april 19.
Files from before this date can be restored.
Files after this data show this problem.
But not all files, probably only the deduplicated files.

I don't think it is a specific BackupAssist problem.
Because i also tried to restore the same files with the windows tools

so i used Diskshadow expose to have the backup i want to restore from available as a disk.
mounted the backup vhdx file,
mounted the data vhdx file with the data to restore
And had similar problems restoring from this.
(I don't remember the exact message, and will repeat this procedure and post the message later)

Re: Cannot restore deduplicated files

Posted: Fri May 12, 2017 3:31 pm
by lucwuyts
The error message is: Error 0x80070780: The file cannot be accessed by the system


The folder i need to restore has 41 files

Only 10 are restored successfully.

Re: Cannot restore deduplicated files

Posted: Fri May 12, 2017 3:58 pm
by lucwuyts
The problem is solved!!

The feature data-deduplication was missing on the host running backupassist.

I installed it, rebooted, and was able to restore all files!