WINDOWS 1002000 PROFESSIONAL RESOURCE KIT [Electronic resources] نسخه متنی

Overview of Windows 2000 File Systems

The file system you use with Windows 2000 determines which of the operating system's advanced features are available to you. To use a Windows 2000-based computer to startup in Microsoft® MS-DOS®, Microsoft® Windows® 3.x, or Microsoft® Windows® 95, use FAT16. For a multiple-boot configuration with Microsoft® Windows® 95 OSR2 or Microsoft® Windows® 98 using very large volumes, you might want to use FAT32. If you are concerned with disk security, performance, and efficiency, you might choose NTFS.

What's New

The version of NTFS that is included with Windows 2000 provides significant enhancements over previous versions. Windows 2000 also includes support for the FAT32 file system.

FAT32 support Users of MS-DOS and Microsoft® Windows NT® version 4.0 and earlier must note that FAT32 is a new option in Windows 2000. This file system, first seen in Windows 95 OSR2 and later in Windows 98, allows FAT users to format much larger volumes than possible with FAT16, and stores files more efficiently on large volumes.

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FAT12, FAT16 and FAT32 are referred to synonymously as FAT unless the differences between them must be noted.

NTFS enhancements Users of MS-DOS, Windows 95, and Windows 98 have a new, more advanced option with NTFS. NTFS, the preferred native file system for Windows 2000, is a much more sophisticated, robust, and secure file system than any of the FAT file systems. Users of Windows NT must also note the many improvements made to NTFS in Windows 2000, including the addition of encryption, disk quotas, reparse points, and so on.

Encryption The Encrypting File System (EFS) provides the core file encryption technology used to store encrypted files on NTFS volumes. EFS keeps files safe from intruders who might gain unauthorized physical access to sensitive, stored data (for example, by stealing a portable computer or external disk drive).

Disk quotas Windows 2000 supports disk quotas for NTFS volumes. You can use disk quotas to monitor and limit disk-space use.

Reparse points Reparse points are new file system objects in NTFS that can be applied to NTFS files or folders. A file or folder that contains a reparse point acquires additional behavior not present in the underlying file system. Reparse points are used by many of the new storage features in Windows 2000, including volume mount points.

Volume mount points Volume mount points are new to NTFS. Based on reparse points, volume mount points allow administrators to graft access to the root of one local volume onto the folder structure of another local volume.

Sparse files Sparse files allow programs to create very large files but consume disk space only as needed.

Distributed link tracking NTFS provides a link-tracking service that maintains the integrity of shortcuts to files as well as OLE links within compound documents.

File System Details

An operating system's ability to access files on a volume depends on the file system with which the volume was formatted. Table 17.1 shows the file system formats supported by various operating systems.

Table 17.1 Operating System and File System Compatibility

You can use long and short file names in both NTFS and FAT volumes. A long file name (LFN) can be up to 255 characters long. Short file names have the 8.3 format and are compatible with MS-DOS and other legacy operating systems.

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8.3 format means that files can have between 1 and 8 characters in the file name. The name must start with a letter or a number and can contain any characters except the following:

. " / [ ] : ; | = , * ? (space)

An 8.3 file name typically has a file name extension between one and three characters long with the same character restrictions. A period separates the file name from the file name extension.

Several special file names are reserved by the system and cannot be used for files or folders:

CON, AUX, COM1, COM2, COM3, COM4, LPT1, LPT2, LPT3, PRN, NUL