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What use is duplication of data if this occurs? RRS feed

  • Question

  • Hi all

    I booted my WHS up this morning to receive all sorts of errors with respect to file conflicts. Logging into the console I discovered one of my HD's was failing (I also received a "An unexpected error has occured in the WHS Storage Manager" error) and calculating size would never finish.

    So looking at the errors I noticed I needed to repair my backup database, which I then consequently did. This resulted, much to my shock and horror, in me losing pretty much EVERY machine backup (I have 9 systems here).

    Still lots of file conflict errors (as well as the error message for the storage manager). Unfortunately I don't have enough disk space left to remove this failing HD, so I've now  removed duplication on all of the folders so I can hopefully get enough storage available to remove the erroring HD (given I've lost my backup database in its entirety I should now have enough).

    However this still isn't working (likely because of the erroring storage manager) and much to my concern, all of the folders and data (that WERE duplicated and now aren't) are still reporting that the data is unhealthy and that file conflicts (actually files missing) is still occurring.

    So my question is how did this happen? My understanding is that duplication should have protected against a media failure however in this instance it's looking like it hasn't. I've still lost data when in fact the data was duplicated over two hd's. Isn't this what WHS's duplication is supposed to protect you from?

    It's also highlights the biggest achilles heel in WHS's arsenal. The absolute single point of failure on the backup database as it's not by default protected/duplicated. I will now be enabling the WHS BDBB add-in to duplicate my backup's as I've likely lost a great portion of data that I shouldn't have.

    Not happy

    Thanks

    Simon

    Wednesday, February 4, 2009 12:36 PM

Answers

  • Hi Simon,
    removing duplication in this situation was a bad idea, since this may have removed the still intact duplicate, while the original was already damaged.
    The files are still there (even if not always accessible, since the main tombstone may point to the failed drive), while duplication is on.
    The only way to fix broken tombstones is to remove the disk via console - with duplication still enabled. Since you have now been to quick with action (assuming you have no backup of shared folders on an external disk?) your only chance to recover some of the data may be the method described in this FAQ.
    Consider the backups lost (they can be redone usually later from the still existing client - consider the client the duplicate for it's backup), since those are not duplicated at all. The client backups are not thought as an archiving solution (which would indeed need more precautions in the database design), but more as an easy recovery feature in case of a client failure.
    The single point of failure is the server itself - with all duplication or whatever nothing can protect it reliable against breaking due to overvoltage, a natural disaster, fire, theft - so there is still a need to create backups of important data on some additional media, which is ideally stored on another place.

    Best greetings from Germany
    Olaf
    Wednesday, February 4, 2009 1:55 PM
    Moderator
  • Remove the failing hard drive physically, then remove it with the console.  This has worked every time for me with the last three failing drives (cept once but MS has fixed that issue).  i have also lost client backups each time but just reback em up.  
    athlon 3400, 2gb ram, 9 drives totaling about 3.5 tbs.
    Thursday, February 5, 2009 1:51 AM

All replies

  • Hi Simon,
    removing duplication in this situation was a bad idea, since this may have removed the still intact duplicate, while the original was already damaged.
    The files are still there (even if not always accessible, since the main tombstone may point to the failed drive), while duplication is on.
    The only way to fix broken tombstones is to remove the disk via console - with duplication still enabled. Since you have now been to quick with action (assuming you have no backup of shared folders on an external disk?) your only chance to recover some of the data may be the method described in this FAQ.
    Consider the backups lost (they can be redone usually later from the still existing client - consider the client the duplicate for it's backup), since those are not duplicated at all. The client backups are not thought as an archiving solution (which would indeed need more precautions in the database design), but more as an easy recovery feature in case of a client failure.
    The single point of failure is the server itself - with all duplication or whatever nothing can protect it reliable against breaking due to overvoltage, a natural disaster, fire, theft - so there is still a need to create backups of important data on some additional media, which is ideally stored on another place.

    Best greetings from Germany
    Olaf
    Wednesday, February 4, 2009 1:55 PM
    Moderator
  • Remove the failing hard drive physically, then remove it with the console.  This has worked every time for me with the last three failing drives (cept once but MS has fixed that issue).  i have also lost client backups each time but just reback em up.  
    athlon 3400, 2gb ram, 9 drives totaling about 3.5 tbs.
    Thursday, February 5, 2009 1:51 AM