Overview
RAID combines drives using defined data-protection or striping schemes. JBOD presents individual disks without RAID protection. Spanning or concatenation combines capacity into a larger logical presentation but does not inherently provide redundancy.
Engineering considerations
RAID 0 and spanning can both increase usable capacity or simplify presentation, but neither provides drive-failure protection. Mirroring and parity RAID add redundancy with different capacity and performance trade-offs.
How to plan it
JBOD can be useful when applications deliberately manage individual disks, but it should not be confused with a resilient array. The correct choice depends on the application, availability requirement, backup strategy and platform capabilities.
Design implications
Whatever layout is selected, document the failure model and recovery process. Storage presentation alone does not establish a backup or disaster-recovery strategy.