Spanned volume
A spanned volume is a formatted partition which data is stored on more than one hard disk, yet appears as one volume.
Spanned volumes are a non-RAID drive architecture, and may be implemented in hardware or software; they may be referred to as Concatenation, SPAN, BIG, or JBOD, though this latter is ambiguous – JBOD may also refer to each physical disk being presented as a separate logical volume.
Drawbacks
Unlike RAID, spanned volumes have no fault-tolerance, so if any disk fails, the data on the whole volume could be lost.
Implementations
In Windows NT, a spanned volume is called a volume set. FAT16/32 and NTFS file systems may be used, and the volume can span up to 32 hard disks, and the system or boot partitions cannot be included in a spanned volume.