Forum Discussion

Tony_Christians's avatar
Tony_Christians
Level 3
15 years ago

Differential restore question

Running Backup exec 2010 on Windows 2003 server. Will restoring a differential backup do deleting of files also? Here is the scenerio. Monday - I do a full backup Tuesday I delete file test.txt Tuesday night I do a differential backup. On Wednesday my server crashes and First I do the full restore from Monday and then do the differential restore from Tuesday. What is the status of the test.txt file after i do the differential restore? Thanks for the answer.
Backup and Recovery
Backup Exec
  • Ken_Putnam's avatar
    Ken_Putnam
    15 years ago
    Gotta disagree with AZC

    No, a differential will NOT delete files, but it will restore any files that were backed up, overwriting any that exist (if you tell it to do so)

    Since TEST.TXT was  backed up on Monday's backups it will be restored when you restore the Monday Full,  and will still be there after you restore the Tuesday DIfferential

    The Symantec respose to this situation is the Synthetic backup.   This uses a previous full (or synthetic) and an incremental to produce a backup set that is the same as it would be if a full were done at that time

6 Replies

Sort By
  • Ken_Putnam's avatar
    Ken_Putnam
    Level 6
    15 years ago
    Gotta disagree with AZC

    No, a differential will NOT delete files, but it will restore any files that were backed up, overwriting any that exist (if you tell it to do so)

    Since TEST.TXT was  backed up on Monday's backups it will be restored when you restore the Monday Full,  and will still be there after you restore the Tuesday DIfferential

    The Symantec respose to this situation is the Synthetic backup.   This uses a previous full (or synthetic) and an incremental to produce a backup set that is the same as it would be if a full were done at that time
  • Rohan_Islam's avatar
    Rohan_Islam
    Level 3
    15 years ago
    Agree with Ken....

    Since TEST.TXT was  backed up on Monday's backups it will be restored when you restore the Monday Full,  and will still be there after you restore the Tuesday DIfferential

  • sksujeet's avatar
    sksujeet
    Level 6
    15 years ago
    Yes offcourse test.txt should be restored

    Here is the situation I will explain:

    Monday - I do a full backup -> you backed up all the file on Monday and they are backed up on tape or disk

    Tuesday I delete file test.txt-> File is no longer in the system so no way to back it up.

    Tuesday night I do a differential backup. -> Differential will backup all the changes that are done after the full backup. Will not backup test.txt as it is not there

    On Monday you restored the data and test.txt will be restored. Now if you run the tuesday differential restore  then it will restore all the data that was backed up on the differential.



  • Tony_Christians's avatar
    Tony_Christians
    Level 3
    15 years ago
    Thanks for answering my question but now I have another.
    Is there any way to preserve these deletes?  The reason I ask is if I have to do a disaster recovery using the Full and differential backups and users deleted files between the full and differential they will wonder why the files are back.  Not to much of a big deal since the way our data grows I doubt if anyone does delete files but it would be nice if there was a way.

  • Ken_Putnam's avatar
    Ken_Putnam
    Level 6
    15 years ago
    As I said before, the Symantec response to this situation is the "Synthetic Backup"

    You take a  full backup, then a incr that is merged with the previous full (or synthetic) and the result is what you would have gotten had you run another full.