“Storage Spaces” is a new feature in Windows 8 and Windows 10 that can combine multiple hard drives into a single virtual drive. It can mirror data across multiple drives for redundancy or combine multiple physical drives into a single pool of storage.
You can even create pools of storage larger than the amount of physical storage space you have available. When the physical storage fills up, you can plug in another drive and take advantage of it with no additional configuration required. Storage Spaces is similar to RAID or LVM on Linux.
Creating a Storage Space
To create a storage space, you’ll have to connect two or more additional drives to your computer – you can’t use your system drive for this. The drives can be either internal or external drives.
You can open the Storage Spaces configuration window from the Control Panel or by bringing up the Start screen with the Windows key, typing “Storage Spaces,” clicking the Settings category and selecting the Storage Spaces shortcut. If you’re using Windows 10 you have to search using the Start Menu instead.
If you haven’t set up a storage space yet, you’ll only see a link to create a new storage space. Once you’ve set up a storage space, information about your system’s storage spaces will appear here.
Select the drives you want to use for the storage space and click the “Create pool” button to continue. You’ll lose any files that are already on the drive – copy any important files off the drives before pooling them. You can add additional drives later.
After selecting the drives to pool, you’ll have to configure your new storage space. The name and drive letter are self-explanatory – the storage space will appear as the drive letter you specify here.
Windows will tell you the maximum physical capacity of your pooled drives, but you can specify an arbitrarily large logical size. For example, you could pool two 20GB drives and select a combined size of 500GB. The storage space will appear to Windows and other programs as a drive that has 500GB of available storage. When the drive begins to fill up and nears the 40GB physical limit, Windows will display a notification in the Action Center, prompting you to add additional physical storage space.
The resiliency type controls how Windows handles your data. There are four options:
- None: Windows will store only a single copy of your data. You’ll lose the data if one of your drives fails, but no space will be used on backups.
- Two-way mirror: Windows will store two copies of your data. If one of your drives fails, you won’t lose your data. This requires at least two drives.
- Three-way mirror: Windows will store three copies of your data. If one or two of your drives fails, you won’t lose your data. This requires at least three drives.
- Parity: Windows stores parity information with the data, protecting you from a single drive failure. Parity uses drive space more efficiently than mirroring, but file access times are slower. Parity is ideal for drives with large, infrequently updated files, such as video files.
After you’ve entered your settings, click the “Create storage space” button and Windows will create and format the storage space.
Using a Storage Space
Your new storage space will appear in Windows Explorer as a normal drive with a single drive letter. The storage space appears no different from a normal, physical drive to Windows and the programs you use.
You can do anything you’d do with a normal drive with the storage. You can even enable BitLocker drive encryption for it.
Managing Storage Spaces
After creating a storage space, you can revisit the Storage Spaces control panel to view information about your storage spaces. From this window, you can view the available space in your storage pool, add additional drives, and create new storage spaces.
If you’re interested in seeing more technical information about the Storage Spaces feature, check out this post on Microsoft’s “Building Windows 8” blog.