NETWORK FILE SYSTEM vs. WINDOWS NT FILE SYSTEM
Introduction to NTFS:
The design goal of NT is provide the extensibility, portability, reliability, compatibility, performance and international support. The extensibility is the crucial thing for the operating system because of the advancement of the technologies. The NT is implemented on the Layered architecture to facilitate over changes. NTFS is designed for many features like data recovery, security, fault tolerance and multiple data stream. The fundamental entity in NTFS is a volume. NTFS does not deal with individual sectors of the disk but it deals with the cluster of the sectors for disk allocation and uses logical cluster numbers (LCN's) as disk addresses.
Key Difference between NTFS and NFS:
NTFS uses the client server architecture and layer architecture approach. NTFS consist of three components - Terminal Server, Remote Desktop Protocol (RDP) and a Super thin client. The Terminal server is capable of directly hosting compatible multi-user-client desktop running on a variety of the hardware. Remote Desktop protocol is based on the T-120 protocol family standards. A multi-channel capable protocol allows for separate virtual channels for carrying serial device communication and presentation data from the server. RDP being completely independent of its transport stack means that we can add other transport drivers for other network protocols with no significant or little changes.
The NTFS's scalability is limited as it can support less processors as compare to the NFS.A file in NTFS is not simple byte stream ,as it is in the NFS, rather it is a structured object consisting of the attributes. each attribute of a file is an independent byte stream that can be created, deleted read and written .Every file is stored in a array structure called Master File Table (MFT).
The NTFS's scalability is limited as it can support less processors as compare to the NFS.A file in NTFS is not simple byte stream ,as it is in the NFS, rather it is a structured object consisting of the attributes. each attribute of a file is an independent byte stream that can be created, deleted read and written .Every file is stored in a array structure called Master File Table (MFT).
NTFS supports the hierarchy of directories and each directory uses the B+ tree structure to store an index of the file name in the directory.
NFS stores the redundant metadata on the disk and recover from the crashes using fsck program to check all the file system data structures, and to restore them forcibly to the consistent state.Restoring them often involves deleting damaged files and freeing data cluster that had been written with user but have not properly recorded in the file system' metadatastructure.This checking can be slow process,and can lose the significant number of data.NTFS takes differnet appproch to the file system robustness. In NTFS ,all the file system adata data structure updates are performed inside transaction.periodically ,a check point record is written to the log i.e before data structure is altered ,the transaction writes a log record that contains redo and undo information,a coomit record is written to the log to signify that transcation has completed.The first time that an NTFS volume is accessed after system start up,NTFS automatically performs file system recovery.
The security of the NTFS is based on the NT model - an open table called MFT is implemented as a file object with a security descriptor stord on the disk as a part of the file and NT security sytem verifies that a process has appropriate authorization to open a handle to a file object.
Sources:
Operating system concepts --Silberschatz and Galvin
www.galaxycomputer.com/Terminal server Architectural Overview.htm