
- •Unit 3. Operating System Software
- •3.1 Structure
- •3.1.1 Layers of Software
- •3.1.2 The bios: Life at the Bottom
- •3.1.3 Process Control
- •3.2 Device Management and Configuration
- •3.2.1 Interrupt Handling
- •Interrupts
- •Interrupt Priority and Nested Interrupts
- •3.2.2 Hardware Attributes
- •Installing Drivers
- •3.2.3 Configuration
- •3.3 Resource Sharing
- •3.3.1 Virtual Memory
- •Virtual Memory
- •3.3.2 File and Printer Sharing
- •3.4 File Systems
- •3.4.1 File Organization
- •3.4.2 File Allocation Table and nt File System
- •Clusters and File Allocation Tables
- •Nt File System
Nt File System
An improvement to the FAT file systems is the New Technology File System (NTFS) used in Windows 2000/NT/XP and other more recent versions of Windows including Windows Vista. In NTFS, the cluster size is variable depending on the size of the logical drives. The cluster size is automatically determined by the NTFS Format utility, thereby, providing a level of flexibility. This flexibility is not available in FAT16 or FAT32. These features enable more efficient allocation of disk space.
One important feature of NTFS is recoverability. NTFS maintain the consistency of data using journaling, keeping a log of each I/O operation that modifies a system file within a logical drive. If the system fails, the file directory structure can be recovered based on the history of the I/O operations performed on the file system. Another feature of the NTFS on Windows is the Encrypted Files System (EFS). EFS enables data to be encrypted as it is saved to disk. NTFS also supports data access control and ownership privileges to restrict unauthorized access to data in a multi-user environment.
The chart below compares NTFS and FAT files systems.
NTFS versus FAT
|
* Values pertain to size limitations during implementation.
Table 1 NTFS versus FAT
Source: Windows 2000: File Systems and Windows XP Professional Resource Kit : Working with File Systems