Desirable features of good distributed file system

Desirable features of a good distributedfile system

Two main purposes of using files:
1. Permanent storage of information on a secondary storage media.
2. Sharing of information between applications.
A file system is a subsystem of the operating system that performs file management activities such as organization, storing, retrieval, naming, sharing, and protection of files.

A good distributed file system provides the following types of services:
 1.Storage service:-Allocation and management of space on a secondary storage device thus providing a logical view of the storage system.
2.True file service:-Includes file-sharing semantics, file-caching mechanism, file replication mechanism, concurrency control, multiple copy update protocol etc.
3.Name/Directory service:-Responsible for directory related activities such as creation and deletion of directories, adding a new file to a directory, deleting a file from a directory, changing the name of a file, moving a file from one directory to another etc.
Desirable features of a good distributed file system:-
a. Structure transparency:-Clients should not know the number or locations of file servers and the storage devices.
Note: multiple file servers provided for performance, scalability, and reliability.
b. Access transparency:-Both local and remote files should be accessible in the same way.
c. Naming transparency:-The name of the file should give no hint as to the location of the file. The name of the file must not be changed when moving from one node to another.
d. Replication transparency:-The clients do not need to know the existence or locations of multiple file copies.
2. User mobility:-User should not force to work on a specific  node but should have the flexibility to work on different nodes at different times.
3. Performance:-The performance of the file system is usually measured as the average amount of time needed to satisfy client requests.
4. Simplicity and ease of use:-User interface to the file system be simple and number of commands should be as small as possible.
5. Scalability:-A good distributed file system should be designed to easily cope with the growth of nodes and users in the system.
6. High availability:-A distributed file system should continue to function in the face of partial failures such as a link failure, a node failure, or a storage device crash. A highly reliable and scalable distributed file system should have multiple and independent file servers controlling multiple and independent storage devices.
7. High reliability:-Probability of loss of stored data should be minimized. System should automatically generate backup copies of critical files.
8. Security:-Users should be confident of the privacy of their data.
9. Heterogeneity:-There should be easy access to shared data on diverse platforms (e.g. Unix workstation, Wintel platform etc).
More topics from Distributed System to read:

DISTRIBUTED SYSTEM covered following topics in these notes.
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.