File System: Files are used for storing the Information of the user; But Files are organized into the System by using a Specific Manner. Generally for arranging all the Files, directories or Folders are used.
A Folder is also called as the Container of the Files in which many Sub directors and Files are Stored. But there is also a Access Method in which data of the File will be accessed by the user.
Means from which Location Information of the File will be Accessible. There are various types of Storage Architectures which specify fro which Locations. File will be Read and from which Locations Data will read and how the data will be Read from the Files.
There are three types of Attributes of the Files
1) Read We can only read the data but we can’t modify the Data of the File.
2) Write We can also write the data and also Read the data
3) Hidden File will not be shown to the user. But these will Remain Saved on the user Computer.
There are two Types of Access in which Files are Read from the System
In the Sequential Method or Access Data of a file is Read from Starting Point to the End Means if we wants to Read the Line then we must have to Travel all the Files. For Example if a File Contains 100 Lines and we wants to Read the 50th Line then we must have to all the Lines all the Lines from 1 to 50.
And In the Indexed File an index has maintained which Stores the Index or the Files which Contains the Address of the File, So that we can Read a File from a Specific Location. For Example in our Books there is an index on thee First Page Which Will Stores all the Page Numbers of all the Topics and we can jump to any Topic with the help of Index.
The File System Architecture Specifies that how the Files will be stored into the Computer system means how the Files will be Stored into the System. Means how the data of the user will be Stored into the Files and how we will Access the data from the File. There are many types of Storage or Space allocation techniques which specify the Criteria by using; the Files will Stores the data into them.
1) Continues Space Allocations: – The Continues space allocation will be used for storing all the data into the Sequence Manner. Means all the data will store by using the Single Memory Block. In this all the data of the File will be stored by using the Continues Memory of the Computer Systems. This makes fastest Accessing of data and this is used in the Sequential Access.
In this when System Finds out the First Address or base Address from the Set of Address of the Files, then this will makes easy for the System to read all the data from the Computer Systems. But for Storing the Data into the Continues Forms, CPU loss his Time because many Times Data any Large from the Existing Space. So that this will create Some Difficulties to find out the Free Space on the disk.
2) Linked Allocation: – This Technique is widely used for storing the contents into the System. In this the Space which is provided to the Files may not be in the Continuous Form and the Data of the Files will be Stored into the Different blocks of the Disks.
This Makes Accessing Difficult for the Processor. Because Operating System will Traverse all the Different Locations and also use Some Jumping Mechanism for Reading the contents from the File in this the First Location will be accessed and after that System will search for the other Locations. But Always Remember that all the Locations will be linked with Each other and all the Locations will be automatically traversed.
3) Index Allocation: – This is also called as Some Advancement into the Linked Space Allocation. This is same as the Linked Space Allocation by it also maintains all the Disk Address into the Form of Indexes. As Every Book Contains an index on the Front Page of the System Like this All the Disk Addresses are Maintained and stored into the Computer System and When a user Request To read the Contents of the File , then the Whole Address will be used by the System by using the index numbers.
For this System also Maintains an index Table which contains the Entry for the data and the Address Means in which Address, which Data has Stored So that this makes the Accessing Fastest and Easy for the Users.