1. JBOD means ‘just a bunch of disks’ and sometimes ‘just a bunch of drives’.

2. It has an array of hard disks that not have been configured according to the RAID (for "redundant array of independent disks") system.

3. JBOD is used in reference to a system that has each individual disk show up an individual logical volume in the computer.

4. Like RAID system that stores the same data redundantly(to achieve fault tolerance) on multiple disks that will appear to the operating system as a single disk, JBOD also makes the disk appear to be single one, it shows that by combining the drives into one larger logical volume.

5. JBOD is multiple physical disks in an external cabinet array connect to a single server, it provides higher storage capacity with increases no. of drives and data is not protected. 

6. The official term for JBOD is “spanning” – used to refer to a computer's hard disks that haven't been configured according to the RAID system to increase fault tolerance and improve data access performance.   


1. JBOD vs. RAID Scalability:  JBODs are preferred by many as they are relatively easy to scale by just adding another drive.  The JBOD configuration also allows for the combined space of all the drives to be used by the end Operating System.  You can also mix different disk sizes in JBOD. RAID treats a collection of drives as a single storage unit, so RAID configurations don’t allow different disk sizes to be used in the array. It requires all drives to be of similar capacity and model type.

2. JBOD vs. RAID Affordability:  SCSI, SAS and Hardware RAIDs are much more pricy than basic SATA disks and Controllers used in JBODs.

RAID is a more expensive solution, largely because it is less flexible and uses higher price point hardware components.

3. JBOD vs. RAID Trends: JBOD has become more and more of a preferred solution as storage becomes more massive and complicated.  Also, as other supporting technologies emerge, any concerns about JBOD in the past that were centered around data recovery and performance have largely gone away.

EBOD (enterprise bunch of disks) is emerging as a new paradigm also. RAID, offers an incredible assortment of high performance products in this category. 

More topics from ISM to read:


EasyExamNotes.com covered following topics in these notes.
  1. ILM
  2. Storage infrastructure
  3. Data proliferation
  4. Evolution of various storage technologies
  5. Data categorization
  6. Integrated VS Modular Array
  7. Component architecture of intelligent disk subsystem
  8. Intelligent disk subsystems overview
  9. Mapping n operations
  10. Storage system architecture
  11. RAID
  12. Hot spare
  13. Striping and Mirroring
  14. SAN security
  15. JBOD
  16. Elements of DAS,NAS,CAS,SAS
  17. Limitations of DAS
  18. Cloud vocabulary
  19. NAS security
  20. Management of DAS,NAS,CAS,SAN
  21. FC Connectivity
  22. Memory virtualization
  23. Data center concepts & requirements
  24. Network virtualization
  25. Server
  26. Architectural Framework ISM
Python Programming ↓ 👆
Java Programming ↓ 👆
JAVA EasyExamNotes.com covered following topics in these notes.
JAVA Programs
Principles of Programming Languages ↓ 👆
Principles of Programming Languages
EasyExamNotes.com covered following topics in these notes.

Previous years solved papers:
A list of Video lectures References:
  1. Sebesta,”Concept of programming Language”, Pearson Edu 
  2. Louden, “Programming Languages: Principles & Practices” , Cengage Learning 
  3. Tucker, “Programming Languages: Principles and paradigms “, Tata McGraw –Hill. 
  4. E Horowitz, "Programming Languages", 2nd Edition, Addison Wesley

    Computer Organization and Architecture ↓ 👆

    Computer Organization and Architecture 

    EasyExamNotes.com covered following topics in these notes.

    1. Structure of desktop computers
    2. Logic gates
    3. Register organization
    4. Bus structure
    5. Addressing modes
    6. Register transfer language
    7. Direct mapping numericals
    8. Register in Assembly Language Programming
    9. Arrays in Assembly Language Programming


    1. William stalling ,“Computer Architecture and Organization” PHI
    2. Morris Mano , “Computer System Organization ”PHI

    Computer Network ↓ 👆
    Computer Network

    EasyExamNotes.com covered following topics in these notes.
    1. Data Link Layer
    2. Framing
    3. Byte count framing method
    4. Flag bytes with byte stuffing framing method
    5. Flag bits with bit stuffing framing method
    6. Physical layer coding violations framing method
    7. Error control in data link layer
    8. Stop and Wait scheme
    9. Sliding Window Protocol
    10. One bit sliding window protocol
    11. A protocol Using Go-Back-N
    12. Selective repeat protocol
    13. Application layer
    1. Andrew S. Tanenbaum, David J. Wetherall, “Computer Networks” Pearson Education.
    2. Douglas E Comer, “Internetworking with TCP/IP Principles, Protocols, And Architecture",Pearson Education
    3. KavehPahlavan, Prashant Krishnamurthy, “Networking Fundamentals”, Wiley Publication.
    4. Ying-Dar Lin, Ren-Hung Hwang, Fred Baker, “Computer Networks: An Open Source Approach”, McGraw Hill.