locked
whs folder duplication RRS feed

  • Question

  • Is whs folder duplication parody based (sort of like raid 5 but not striped) where only the capacity of one drive (parody drive) is lost? Or is it more like raid 1 accross more than two drives and half of the storage is lost to redundacy? -drwebster93
    Tuesday, September 9, 2008 4:17 AM

Answers

  • Windows Home Server share duplication is neither. It's not RAID at all. It operates at the file system level to put normal copies of files on two physical drives in your server. While this is similar to RAID 1, it doesn't reserve an entire disk for this purpose; files are created and copied as needed, so disk space is conserved.
    I'm not on the WHS team, I just post a lot. :)
    Tuesday, September 9, 2008 12:02 PM
    Moderator
  • In theory, if you filled your server up with shared files in duplicated shares, yes you'd lose half your storage. However, that storage isn't automatically cut in half up front, as it would be with RAID 1.

    Tombstones are pointers to where the actual files reside on your server. They are small files (4k each).

    For the (likely) final word on RAID, see this WHS team blog post.

    I'm not on the WHS team, I just post a lot. :)
    • Marked as answer by drwebster93 Wednesday, September 10, 2008 11:32 PM
    Tuesday, September 9, 2008 5:25 PM
    Moderator

All replies

  • Hi,
    Folder duplication for the Shared Folders is duplicated across different disks, as long as you have more than one.
    If you have, say, three drives, then the tombstones will be on the system drive, while a copy of any particular file will then be stored on each of the two other drives.
    If you then loose a data disk, not only will there still be a file copy remaining, but WHS will then rebuild the lost copy when a replacement disk is installed.

    Colin

    If anyone answers your query successfully, please mark it as 'Helpful', to guide other users.
    Tuesday, September 9, 2008 9:03 AM
    Moderator
  • Windows Home Server share duplication is neither. It's not RAID at all. It operates at the file system level to put normal copies of files on two physical drives in your server. While this is similar to RAID 1, it doesn't reserve an entire disk for this purpose; files are created and copied as needed, so disk space is conserved.
    I'm not on the WHS team, I just post a lot. :)
    Tuesday, September 9, 2008 12:02 PM
    Moderator
  • If I where to set all of my shared folders to be duplicated, wouldn't I in theory loose half of my storage because each file would be stored twice in my storage pool, only allowing half the files to be stored that I would normally be able to store without duplication?  Also, if each file is physically duplicated on two drives, what do the tomb stones on the system drive have to do with anything?

    -drwebster93
    Tuesday, September 9, 2008 12:38 PM
  • depends, how your storage is organized. With more than 2 disks (which you also would need for RAID5) you will no longer loose half of the storage, since the data of the shared folders is stored on only 2 of the disks.

    While I would find RAID 5 a great idea, there are possible reasons, why this has not be implemented.
    I think of reasons like:
    Handling of a broken disk
    If a disk does not work longer, how an average user determines, which disk is exactly broken? A RAID 5 goes down, if the second disk is pulled, while one is already broken.
    External disk support
    USB disks cannot be supported by RAID.
    Using disks of different size
    RAID arrays prefer identical disks, while you can add into your home server, what is just the most interesting component available in the market (or you still recovered from another PC).
    Adding storage
    into an existing RAID is possible, but also more complicated.

    The tombstones are pointers to the files stored on the other disks. So if one disk fails, you still should not need to know, where the files are stored, but the pointer will return the file to you, if you want to access it (in case folder duplication is on).

    Best greetings from Germany
    Olaf
    Tuesday, September 9, 2008 1:16 PM
    Moderator
  • In theory, if you filled your server up with shared files in duplicated shares, yes you'd lose half your storage. However, that storage isn't automatically cut in half up front, as it would be with RAID 1.

    Tombstones are pointers to where the actual files reside on your server. They are small files (4k each).

    For the (likely) final word on RAID, see this WHS team blog post.

    I'm not on the WHS team, I just post a lot. :)
    • Marked as answer by drwebster93 Wednesday, September 10, 2008 11:32 PM
    Tuesday, September 9, 2008 5:25 PM
    Moderator