Many motherboards, storage controllers and even standalone multi-disk units support JBOD (Just a Bunch of Disks) which allows multiple disks to be attached to a computer and presented to the host operating system as a single drive. Windows 10 has introduced a facility called Storage Spaces, which allows unallocated storage space on any attached disks to be combined together to create a single data volume.
Neither of these include any fault tolerance or redundancy and may complicated the data recovery process in the event of even one drive failing, particularly when Storage Spaces has been used in simple mode. In concept these appear to be good ideas, as they allow large volumes to be created, but it puts any data stored on them at risk. Storage Spaces has replaced a similar system which was available in some older versions of Windows.
Data Spanned Across Disks
Apart from being able to create a single large data volume, using a JBOD configuration or Storage Spaces in simple mode does not provide any advantages over any other method, even setting up a set of hard disks as a RAID 0 array.
If you wish to use such a configuration it is important that all data being stored is regularly backed up to ensure that in the event of failure, your data can be restored without resorting to data recovery, which may be a complex process. Determining the order of spanned sections of drives can sometimes be difficult to determine.
Storage Spaces Mirroring and Parity
Storage Spaces does provide the possibility to configure mirroring and even parity, which uses a RAID 5 scheme. These configurations are preferable to using the simple mode, which spans a volume across different drives.
Mirroring allows the use of two or even three drives, which provides the maximum possible redundancy, but as it is controlled by the operating system will use some CPU. The use of RAID 5, especially through the operating system poses a much higher risk, but still preferable to no redundancy at all.
Data Recovery from JBOD or Storage Spaces
The use of the RAID 5 configuration or mirroring through Storage Spaces provides a high level of recoverability in the event of failure. The use of simple mode or a JBOD provides no fault tolerance and the chances of successful data recovery is determined by the level of damage which has been suffered to the failed drive.
If you require a larger data volume a better option to Storage Spaces is to install a dedicated RAID controller. If you are using a standalone unit, it is much better to use a RAID level which provides fault tolerance, thereby increasing the chances of a successful data recovery in the event of a failure.