Windows 8.1 Disk Mirroring RRS feed

  • Question

  • Hello,

    I am running a Windows 8.1, 32 bit. My C: drive contains Windows and I have 2 additional 3TB hard drives which are mirrored using Windows 8.1 storage spaces tools. I do not boot off of these disks and only use them for media and storage. I have a few questions:

    1. As I am only using these disks for storage of files and not booting, if one fails, will the second one be recognized and useable with no data loss? I have seen many people warn against using Storage Spaces but it seems they are all talking about issues on a mirrored boot drive - that is not my case.

    2. I would like to upgrade to 64 bi as I want to add more than 4GB of RAM to my PC. I have media and a valid key, however, will I have to re-mirror the drives using storage spaces and will I lose the date on either 1 or both of them? Does Storage Spaces do some compare to see that the disks are identical?

    3. As the drives I want to mirror are both 3TB, will this cause an issue due to the size? I converted them to GPT when I initially installed 8.1 32 Bit. Will I have to do the same when I reinstall 64 bit or will they already be recognized?

    Any help would be much appreciated.

    • Edited by Ellio Tuesday, March 25, 2014 8:21 PM typo
    Tuesday, March 25, 2014 8:19 PM


  • Hi,

    First,we need to understand mirror storage layout.

    Mirror. Data is duplicated on two or three physical disks, increasing reliability, but reducing capacity. This storage layout requires at least two disks to protect you from a single disk failure, or at least five disks to protect you from two simultaneous disk failures.

    Storage Spaces can automatically rebuild mirror and parity spaces in which a disk fails by using dedicated disks that are reserved for replacing failed disks (hot spares).

    So,the data isn't lost.

    Regarding your second and third issues, Storage Spaces records information about pools and storage spaces on the physical disks that compose the storage pool.

    Therefore, your pool and storage spaces are preserved when you move an entire storage pool and its physical disks from one computer to another.

    Note: for parity spaces you must backup your data and delete the parity spaces. At this point, you may upgrade or perform a clean install of Windows 8. After the upgrade or clean installation is complete, you may recreate parity spaces and restore your data.

    You can refer to the following article:


    Hope this helps.


    Kelvin Xu
    TechNet Community Support

    Wednesday, March 26, 2014 9:22 AM