JBOF

Just a Bunch of Flashdrives (JBOF)
This term describes a simple array of SAS (Serial Attached SCSI) or SATA (Serial ATA) interface Solid-State flash storage devices or SSD (Solid-State Disk). These devices use SLC (Single Layer Cell) or MLC (Multi-Layer Cell) Nand flash devices with a SAS or SATA controller interface that makes the flash memory appear like a disk drive when attached to a server SAS/SATA HBA (Host Bus Adapter). The JBOF serves a very similar purpose to a JBOD and in fact the first JBOF was in fact built using an off-the-shelf JBOD populated with Intel X25 SLC SSDs using an AIC JBOD with 10 2.5" small-form factor SAS expansion bays.
JBOF enclosures provide power to each SSD, a backplane or midplane with a SAS expander, and ability to hot-plug drives to exapand capacity or replace failed devices. The enclosure can also serve as a JBOD (Just a Bunch of Disk) using common form factor HDDs (Hard Disk Drives) that use rotational media and a mechanical actuator to position a read/write head over magnetically recorded data tracks.
The term JBOF was first used by Atrato Inc., a company located in Westminster Colorado to describe the use of JBODs and SSD for the new purpose of scaling server SAS attached flash tiers. Atrato has developed hybrid storage pools composed of both SSD flash and HDDs with software to manage these devices at a block level for use on Storage Area Networks (SANs).
In contrast to the JBOF, a number of Storage Class Memory expansion techniques use PCI-e (Peripheral Component Interconnect Express) server I/O channel integration of flash memory PCI-e cards such as FusionIO or with external flash storage appliances such as the Violin Scalable Memory appliance.
At this point in time, both SAN attached flash tiers and server PCI-e I/O channel attached flash tiers have come into more common use in data centers as Storage Class Memory has evolved to capacities, performance, and reliability levels that are competitive with hard disk drive technology.
The term JBOF clearly distinguishes expansion via SAN protocols like SAS from server expansion methods through PCI-e and is simply a refinement of the JBOD. The acronym has come into wider use quickly .

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