Microsoft Windows File System in Operating System

This is an PPT of Operating System. It include the following topic"Microsoft Windows File System in Operating System".

1. BIRLA INSTITUTE OF TECHNOLOGY SAJAN SINGH RATHORE Roll No. :- MCA/25019/18

2. In Windows platform there are many disk file system. Microsoft Windows employs two major file systems : NTFS(New Technology File System) the primary format most modern versions of this os use by default , and FAT(File Allocation Table) , which was inherited from old DOS and has ExFAT(Extended File Allocation Table)as its later extension. In addition the ReFS(Resilient File System ) file system was developed by Microsoft as a new generation file system for server computers starting from windows server 2012. WINDOWS FILE SYSTEMS

3. In the early days of computing, Microsoft developed a file system, in collaboration with IBM ,which was named as FAT file system. FAT file system was developed to meet the requirements of storage devices at that time, which used to be very limited in size. Later on as the size of storage devices grew, FAT file system encountered many problems, so NTFS came into existence. HISTORY

4. FAT is one of the simplest file system types, which has been around since the 1980s. It consists of the file system boot sector or superblock , the file system block allocation table (referred as the File Allocation Table)and plain storage space for storing files and folders. Files in FAT are stored in directories , each defining a file or extended attributes of a file (example  a long file name ). A file record attributes the first block of a file . Any text block can be found through the block allocation table by using it as a linked list. FAT was used in MSDOS and in early versions of windows such as 95 and 98.it stores the information about all the files on the disk. File Allocation Table

5. FAT TABLE  it contains pointers to every cluster on the disk. It indicates the no. of the next cluster on the disk . it indicates the end of a cluster. Tells whether a particular cluster is empty or not . ROOT DIRECTORY  IT is the primary directory of the disk. DATA AREA  This is the place where actual data is stored on the disk. it spans across the remaining sectors of the disk. FAT – TABLE LAYOUT

6. Fat file system was designed for disk of small size(up to few GBs),but later on the as the high capacity disks came into use, FAT file system could not support them. FAT file system could not support the application required Recoverability, fault tolerance and file security. Especially in corporate world, where recoverability and reliability was of great importance, FAT file system loose it ways to NTFS PROBLEMS IN FAT

7. In NTFS every sector is of 512 bytes. Each cluster consist of 2 sectors. Size of each cluster =2*512Bytes 1024 Bytes or 1KB • Let the size of the file = 2000Bytes. So NTFS will allocate 2 clusters(or 4 sectors). The NTFS file system is not applicable for MS DOS, Windows 95, and Windows 98. HOW DOES NTFS FILE SYSTEM STORES DATA ON DISK

8. Developed by Microsoft and was included in Windows like XP, Vista ,2007 and 2008. NTFS supersedes FAT and has many technical improvements which was missing in FAT. It uses advanced data structures like B+ trees. It is more reliable as compared to FAT. Includes features like security, compression encryption, journaling, Indexing. NTFS-New Technology File System

9. Its is like an Index Stores Information about every file and table which is stored in the volume on a disk. There is at least one record for every file and directory. It stores the details like , type, size, date/time of the creation of the file, date/time about the recent modification and author identity. MASTER FILE TABLE

10. File system employ five techniques to provide high file access performance – Use of efficient data structures  Directories are organized by using data structures that facilitate fast search. Effective disk allocation  Disk space is allocated to a file in such a manner that little disk head movement and rotational delays are involved in processing of a sequential file. Caching  part of memory is used as a cache for data stored on an I/O device. PERFORMANCE OF FILE SYSTEM

11. Buffering  A buffer is a memory area that is used to store data temporarily . the file system loads data from an I/O device into a buffer before a process needs it so that the process can access the data without having to wait for an I/O operation to complete. Converse actions are performed when a process wishes to write data in a file. Disk scheduling  I/O operations on a disk are performed in an order that reduce disk head movement it ensures high throughput of a disk. PERFORMANCE OF FILE SYSTEM

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