JBOD

Much of this chapter has focused on discussing disk storage subsystems that incorporate storage address space management as a key feature. A lower-cost alternative is JBOD, short for just a bunch of disks. JBOD does not provide redundancy, address space management, caching, or storage applications. It simply provides power and packaging benefits and centralized access to a collection of disk drives.

JBOD cabinets have a number of physical ports, and the disks inside are made available through LUNs assigned to those ports. JBOD subsystems export storage as raw disks without first partitioning them or creating redundancy with disk mirroring or RAID arrays. Redundancy is achieved through the use of host-based volume management software or through virtualization modules running in network switches and storage appliances.

Hot swapping might be supported if the JBOD cabinet has been designed to support removing and inserting devices while operating. System administrators are responsible for ensuring that all I/O operations are stopped to affected JBOD disk drives before removing and replacing disk drives.