JBOD Explained: Just a Bunch of Disks vs RAID for Server+ and A+
JBOD stands for Just a Bunch of Disks — occasionally written as Just a Bunch of Drives. The name is almost aggressively plain, and it describes exactly what it is: several physical drives attached to a system without being combined into a RAID array. JBOD gives you capacity and flexibility. It gives you no redundancy and no performance gain. Everything about it follows from that trade. The Two Things People Mean by JBOD The term gets used loosely, and exams distinguish between two arrangements. Independent disks. Each drive is presented to the operating system separately, with its own volume and drive letter. Four 4 TB disks become four 4 TB volumes. This is the literal reading of the name. Spanning, or concatenation. Drives are joined end to end into one large logical volume. Four 4 TB disks become a single 16 TB volume. Data fills the first disk, then continues onto the second, and so on. This is sometimes called BIG or SPAN. The distinction matters for failure behavi...