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BE 2015 Differential Restore Questions

We have Backup Exec 2015 backing up to a Deduplicated Disk Storage. Yesterday we had an issue arise in which I had to restore from the previous nights differential backups and I'm wondering if someone could help explain the behavior I saw during the restores.

  • Restore 1 - differential restore with the setting of "Overwrite the files on disk only if it is older" selected. This restore job took much longer than we anticipated, it only was restoring several GB's of files but the job took hours to finish. It seemed to scan every single file and folder despite the fact only some of those were going to be restored. I'm guessing it had somehting to do with it chdecking the file stamps on everything but why if it only needs to restore only the changed files?
  • Restore 2 - differential restore with the setting of "Restore over existing files" selected. This restore job took less time to complete than the previous one did despite the fact it was restoring much more data. The job log said it restored 10795 files when the number of actual files that actually needed to be restored was much less than this. Can someone tell me why this log says this?

Thanks!

1 Solution

Accepted Solutions
Accepted Solution!

Were you restoring from the

Were you restoring from the Point in TIme Wizard or the Backup Set Wizard? - basically the point in time will assemble a synthetic view which includes the full meaning it is difficult to select only the differential files, which means it might have restored some of the full and differential as one restroe job. The Backup Set restore will only restore the differential data

 

If you chose one method for one job and one for the other it is possible that would also create a difference in performance.

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6 Replies

Were these restores both from

Were these restores both from tape or disk?  Deduplication restores from tape will take longer because of the rehydration process.

Both restores were from the

Both restores were from the deduplication disk.

The behavior that you

The behavior that you observed is true regardless of the media that the restore is from. Restore 1 - without scanning each file, how does BE knows which are the changes files? Restore 2 - The number of files that you quoted are the files which are eligible for the restore. Some are not restored because of the condition imposed
Accepted Solution!

Were you restoring from the

Were you restoring from the Point in TIme Wizard or the Backup Set Wizard? - basically the point in time will assemble a synthetic view which includes the full meaning it is difficult to select only the differential files, which means it might have restored some of the full and differential as one restroe job. The Backup Set restore will only restore the differential data

 

If you chose one method for one job and one for the other it is possible that would also create a difference in performance.

View solution in original post

For restore 1, I would asume

For restore 1, I would asume it would only care about scanning the differential files not every single file and folder which is what it seemed to be doing.

For restore 2, are you sure that's the case? What you are saying is the log is basically lying to me which makes no sense to me. If a log says it "restored X files" I would assume it would have actually restored that exact amount of files.

Thanks!

Yes, I did use the Point in

Yes, I did use the Point in Time Wizard and going through both of the wizards right now I see what you are saying as I am only seeing the changed files in the Backup Set wizard. Looks like I chose incorrectly but at least I know for the future.

Thanks!