JBOD (just a bunch of disks or just a bunch of drives)

JBOD (which stands for "just a bunch of disks") generally refers to a collection of

hard disks that have not been
configured to act as a redundant array of independent disks (RAID)
array.

RAID arrays write data across multiple disks as a way of storing data
redundantly (to achieve
fault tolerance) or to
stripe data across multiple disks to get better performance than any one disk could provide on its own. Typically, a RAID array will appear to the

operating system as a single disk.

JBOD is an alternative to using a RAID configuration. Rather than configuring a storage array to use a RAID level, the disks within the array are either spanned or treated as independent disks.

Spanning configurations use a technique called
concatenation to combine the capacity of all of the disks into a single, large logical disk. Although some RAID levels also concatenate disks, numbered RAID levels generally use striping or
parity while JBOD does not.



JBOD means the individual disks are presented (to a
server) with no amalgamation, pooling or structure applied. The term is in widespread use, especially in the context of computers that have software
volume management, such as LVM (AIX,

HP-UX,
Linux), DiskSuite (Solaris), ZFS (Solaris), Veritas Volume Manager (Unixes), Windows and so on.