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File System Basics

The hard disk drive used as secondary storage device in the computing system provide  place to store data. The only way to store and access data on a hard disk drive is by either specifying the data’s physical location in terms of cylinder, head, and sector or by its logical location the block number on the disk. For a programmer specifying and referring the data like this is too difficult. So the operating system takes care of this by means of providing a good file system.

The operating system easily keeps track of the things stored on disks. It is nothing but a way of filing data in an easily accessible way. This is the major role played by the file system. In order to access such data on the disk the programmer is required to write ‘file-handling’ programs. The data on the secondary storage is stored only by means of file.

With reference to Operating System like "Linux", a File System is the whole structure in which the FILES are organized, stored and named especially for the users of the system.

File system treats different sets of data as files. Each file is separate from the other. Along with the A data stored within it, the file system includes additional information for each file like
  • The name of the file.
  • The access permissions on the file
  •  The time and date of creation, access, and modification of the file.


Using the available file system the user or many users can create many files. When all these files are at one place the identification is difficult for the users. The file system provides certain mechanism to make it easier to group related files together. The most commonly used mechanism is the directory structure’. The directory structure or simply directory is regularly implemented as a special type of file. The directories make it possible to create hierarchical structures of files and sub directories.

The file systems vary in implementation details. It means that all the file systems cannot be accessed by all the operating systems. The operating system ‘Linux’ includes support for many popular file systems. So, it is possible to access the file systems of other operating systems with ease. This is particularly useful in dual-boot scenarios, and when migrating files from one operating system to another.

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             In memory the linked list is stored in scattered cells (locations).The memory for each node is allocated dynamically means as and when required. So the Linked List can increase as per the user wish and the size is not fixed, it can vary.

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      Suppose next node is allocated at an address 506, so the list becomes,



  Suppose next node is allocated with an address with an address 10,s the list become,


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