Component architecture of intelligent disk subsystems


Architecture of intelligent Disk subsystem:

1. A disk subsystem is a hard disk server.

2. Servers are connected to the connection port of the subsystem using standard I/O techniques such as SCSI, fibre channel etc.

3. The internal structure of the disk subsystem is completely hidden from the server. The server sees on the hard disks.

4. The connection ports are extended to the hard disk subsystem by means of internal I/O channels.

5. A controller lies between connection ports and hard disks.

6. The controller increases the data availability and data access performance with the help of RAID (Redundant Array of Independent Disks)

7. Some controllers serve as instant copiers and remote mirroring.

8. A cache is also used to accelerate read and write access to the server.
Fig. Servers are connected to the disk subsystems via the port

9. Small disk subsystems have 1 to 2 connections for servers or storage networks. 6-8 hard disks capable of storing 500 GB of data.

10. Larger disk subsystems have more than 10 ports, redundant controllers & several I/O channels. Can store 10 tera bytes of data.

Python Programming ↓ 👆
Java Programming ↓ 👆
JAVA covered following topics in these notes.
JAVA Programs
Principles of Programming Languages ↓ 👆
Principles of Programming Languages 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 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 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.