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Folder Duplication Size RRS feed

  • Question

  • I have about 8TB of data in my storage pool.  I'm getting some really interesting numbers when I turn folder duplication on.

    I've read through the forums that folder duplication duplicates the data 1 for 1 with about an additional 6% for overhead.

    I recently had about 10TB JUST FOR folder duplication (I have a storage pool of 26TB) with another 2 TB to synchronize.  So it would have been 12TB of protection for 8TB of data

    I turned off folder duplication and it's leaving me with about 4TB showing as duplicated data.  I have run check and repair and it doesn't seem to reduce the number.

    Any ideas if this is correct or not and if not, how to fix it?

    Friday, October 8, 2010 2:27 AM

Answers

  • Perfect - thanks for the quick response!
    Thanks. Paul Carvajal
    • Marked as answer by Paul Carvajal Wednesday, October 13, 2010 1:45 AM
    Wednesday, October 13, 2010 1:44 AM

All replies

  • How many drives is that?  13?  or more?  There are issue with more the 10 drives, it's in the documentation.  Perhaps this is related to that.  File a bug report either way.
    athlon 3400, 2gb ram, 7 drives totaling about 6.5 tbs.
    Saturday, October 9, 2010 12:37 AM
  • With 26 TB of storage, the ECC overhead (12% off the top) will be over 3 TB; that will show up as "Data protection". If you haven't turned it off, your backup database will have duplication turned on, and that will also show up as "Data protection". And I believe that shadow copies, if not disabled, also show up as "data protection". Finally, NTFS uses metafiles to store critical information about the file system. Losing those metafiles would render your data inaccessible. I believe those metafiles are duplicated on every disk, since you can connect a single disk from one Vail installaiton to another and access whatever files might be on it.

    So having 4 TB of "Data Protection" is probably not unreasonable.


    I'm not on the WHS team, I just post a lot. :)
    Saturday, October 9, 2010 1:49 PM
    Moderator
  • Thanks for the replies

    I DO HAVE data duplication AND shadow copies turned OFF and still have 4TB showing as data protection.

    In reading your response, am I understanding correctly 12% is set aside for "Data Protection" whether or not I have any data on it (it's based upon the drive pool size)?  Again, I have a drive pool size of 26TB, 8TB of data, and 4TB for "Data Protection" with data duplication and shadow copies turned off.

    Thanks again for the assistance!

    Tuesday, October 12, 2010 4:38 PM
  • As far as I can tell, yes, approximately 12% is immediately set aside for data protection, whether you have any data or not. That would be a bit more than 3 TB in your case. The NTFS metafiles could add up to a significant amount of data, too, since the metafiles for all of your shares really need to be duplicated on absolutely every disk in server storage. Otherwise, you could lose all of your files far too easily in the event of server failure.

    All things considered, I don't feel like your ~4 TB of "Data protection" is completely beyond the bounds of reason.


    I'm not on the WHS team, I just post a lot. :)
    Tuesday, October 12, 2010 4:52 PM
    Moderator
  • Perfect - thanks for the quick response!
    Thanks. Paul Carvajal
    • Marked as answer by Paul Carvajal Wednesday, October 13, 2010 1:45 AM
    Wednesday, October 13, 2010 1:44 AM