Advantages of Using NTFS


NTFS provides performance, reliability, and advanced features not found in any version of FAT. Use NTFS wherever possible to gain the maximum benefits from Windows XP Professional, including the following:

Robust, reliable performance

  • NTFS guarantees the consistency of the volume by using standard transaction logging and recovery techniques. In the event of a system failure, NTFS uses its log file and checkpoint information to restore the consistency of the file system when the computer is restarted.

  • In the event of a bad-sector error, NTFS dynamically remaps the cluster containing the bad sector and allocates a new cluster for the data. NTFS also marks the cluster as bad and no longer uses it.

Built-in security features

  • When you set permissions on a file or folder, you specify the groups and users whose access you want to restrict or allow, and then select the type of access. For example, you can let one group read the contents of a file, let another group make changes to the file, and prevent all other groups from accessing the file.

  • The Encrypting File System (EFS) is the technology used to store encrypted files on NTFS volumes. After you encrypt a file or folder, you work with the encrypted file or folder just as you do with any other files and folders. However, an intruder who tries to access your encrypted files or folders is prevented from doing so, even if the intruder has physical access to the computer.

Supports large volumes

  • Using the default cluster size (4 KB) for large volumes, you can create an NTFS volume up to 16 terabytes. You can create NTFS volumes up to 256 terabytes using the maximum cluster size of 64 KB. NTFS also supports larger files and more files per volume than FAT.

  • NTFS manages disk space more efficiently than FAT by using smaller cluster sizes. For example, a 30-GB NTFS volume uses 4-KB clusters. The same volume formatted by using FAT32 uses 16-KB clusters. Using smaller clusters reduces wasted space on hard disks.

Designed for storage growth

  • By enabling disk quotas, you can track and control disk space usage for NTFS volumes. You can configure whether users are allowed to exceed their limit, and you can also configure Windows XP Professional to log an event when a user exceeds a specified warning level or quota limit.

  • To create extra disk space, you can compress files on NTFS volumes. Compressed files can be read and written by any Windows-based application without first being decompressed by another program.

  • If you run out of drive letters or need to create additional space that is accessible from an existing folder, you can mount a volume at any empty folder on a local NTFS volume to create a mounted drive. Mounted drives make data more accessible and give you the flexibility to manage data storage based on your work environment and system usage.

  • You can increase the size of most NTFS volumes by adding unallocated space from the same disk or from another disk. For more information about increasing the size of NTFS volumes, see Disk Management in this book.

Other advanced features found only on NTFS volumes

  • Distributed link tracking maintains the integrity of shortcuts and OLE links. You can rename source files, move them to NTFS volumes on different computers within a Windows 2000 domain, change the computer name or folder name that stores the target all without breaking the shortcut or OLE links.

  • Sparse files consist of large, consecutive areas of zeroes. NTFS manages sparse files by tracking the starting and ending point of the sparse file, as well as its useful (non-zero) data. The unused space in a sparse file is made available as free space.

  • The NTFS change journal provides a persistent log of changes made to files on a volume. NTFS maintains the change journal by tracking information about added, deleted, and modified files for each volume. Programs such as Indexing Service can take advantage of the change journal to boost search performance.

  • Hard links are NTFS-based links to a file on an NTFS volume. By creating hard links, you can have a single file in multiple folders without duplicating the file. You can also create multiple hard links for a file in a folder if you use different file names for the hard links. Because all of the hard links reference the same file, applications can open any of the hard links and modify the file.

When to Use FAT

If your computer runs only Windows XP Professional and you do not plan to install other operating systems, use NTFS. However, if you have other operating systems installed and want to access the volumes, you must use FAT16 or FAT32, depending on which operating systems are on your computer. For example, to start a Windows XP Professional based computer in Microsoft MS DOS, Microsoft Windows 3.x, or Microsoft Windows 95, you must use FAT16. For a multiple-boot configuration that has Microsoft Windows 95 OEM Service Release 2 (OSR2), Microsoft Windows 98, or Microsoft Windows Millennium Edition (Me), use FAT32. Table 13-3 shows the file system formats supported by various operating systems.

Table 13-3: Operating System and File System Compatibility

Operating System

FAT16

FAT32

NTFS

Windows XP

X

X

X

Windows 2000

X

X

X

Windows NT 4.0*

X

 

X

Windows 95 OSR2, Windows 98, and Windows Me

X

X

 

Windows 95 (prior to OSR2)

X

   

MS-DOS

X

   

*Computers running Windows NT 4.0 require Service Pack 4 or later to access NTFS volumes previously mounted by Windows 2000 or Windows XP Professional.

In multiple-boot configurations, you can use NTFS for the Windows NT 4.0 with Service Pack 4 or later boot volume, Windows 2000 boot volume, or Windows XP boot volume if you do not want to access these volumes from other operating systems. However, you must format the system volume according to Table 13-3 if you want to start other operating systems. For more information about NTFS compatibility in computers running Windows NT 4.0 and Windows XP Professional, see NTFS Compatibility with Windows NT 4.0 later in this chapter. For more information about the system and boot volumes, see Disk Management in this book.

Although NTFS is the preferred file system for hard disks, Windows XP Professional uses FAT12 when you format floppy disks and FAT32 when you format DVD-RAM discs. For removable media that can be ejected unexpectedly, you must use FAT16 or FAT32. NTFS is disabled for some removable media because NTFS does not flush data to the disk immediately, and removing NTFS-formatted media without using the Safe Removal application can result in data loss.

If you do not plan on removing the media and want to use NTFS, you can change the Safe Removal policy.

To enable NTFS on removable media

  1. In Device Manager, right-click the device, and then click Properties.

  2. On the Policies tab, click Optimize for performance.

For more information about removing disks and the Safe Removal policies, see Managing Devices in this book.

You no longer need to use FAT for the system and boot volumes because Windows XP Professional offers two troubleshooting tools designed to access NTFS volumes:

  • Safe Mode starts Windows XP Professional by using only the basic set of device drivers and system services loaded.

  • Recovery Console is a special command-line environment that enables you to copy system files from the operating system CD, fix disk errors, and otherwise troubleshoot system problems without installing a second copy of the operating system.

For more information about Safe Mode and the Recovery Console, see Tools for Troubleshooting in this book.

Cluster Size

A cluster (or allocation unit) is the smallest amount of disk space that can be allocated to hold a file. All file systems used by Windows XP Professional organize hard disks based on cluster size, which is determined by the number of sectors that the cluster contains. For example, on a disk that uses 512-byte sectors, a 512-byte cluster contains one sector, whereas a 4-KB cluster contains eight sectors.

FAT16, FAT32, and NTFS each use different cluster sizes depending on the size of the volume, and each file system has a maximum number of clusters it can support. The smaller the cluster size, the more efficiently a disk stores information because unused space within a cluster cannot be used by other files. And the more clusters supported, the larger the volumes you can create and format by using a particular file system.

Table 13-4 provides a comparison of FAT16, FAT32, and NTFS volume and default cluster sizes.

Table 13-4: Default Cluster Sizes for Volumes with Windows XP Professional File Systems

Volume Size

FAT16 Cluster Size

FAT32 Cluster Size

NTFS Cluster Size

7 MB 16 MB

2 KB

Not supported

512 bytes

17 MB 32 MB

512 bytes

Not supported

512 bytes

33 MB 64 MB

1 KB

512 bytes

512 bytes

65 MB 128 MB

2 KB

1 KB

512 bytes

129 MB 256 MB

4 KB

2 KB

512 bytes

257 MB 512 MB

8 KB

4 KB

512 bytes

513 MB 1,024 MB

16 KB

4 KB

1 KB

1,025 MB 2 GB

32 KB

4 KB

2 KB

2 GB 4 GB

64 KB

4 KB

4 KB

4 GB 8 GB

Not supported

4 KB

4 KB

8 GB 16 GB

Not supported

8 KB

4 KB

16 GB 32 GB

Not supported

16 KB

4 KB

32 GB 2 terabytes

Not supported

Not supported*

4 KB

*Windows XP Professional formats FAT32 volumes up to 32 GB regardless of cluster size. To format volumes larger than 32 GB, you must use NTFS. However, Windows XP Professional can mount FAT32 volumes larger than 32 GB that were created by other operating systems.

In the Disk Management snap-in, you can specify a cluster size of up to 64 KB when you format a volume. If you use the format command to format a volume, but do not specify a cluster size by using the /a:size parameter, the default values in Table 13-4 are used. If you want to change the cluster size after the volume is formatted, you must reformat the volume.

Before you choose a cluster size other than the default, note the following important limitations:

  • For Microsoft Windows NT, Windows 2000, and Windows XP Professional, the cluster size of FAT16 volumes from 2 GB through 4 GB is 64 KB, which can create compatibility issues with some applications. For example, setup programs do not compute free space properly on a volume with 64-KB clusters and cannot run because of a perceived lack of free space. For this reason, you must use either NTFS or FAT32 to format volumes larger than 2 GB. The format command in Windows XP Professional displays a warning and asks for a confirmation before formatting a volume that has 64-KB clusters using FAT16.

  • Windows XP Professional, like Windows NT 4.0 and Windows 2000, supports file compression. Because file compression is not supported on cluster sizes above 4 KB, the default NTFS cluster size for Windows XP Professional never exceeds 4 KB. For more information about NTFS compression, see File Compression later in this chapter.

To check the cluster size of an existing volume, use the chkdsk command or the fsutil fsinfo ntfsinfo command. For more information about using Chkdsk, see Troubleshooting Disks and File Systems in this book. For more information about using Fsutil, see Windows XP Professional Help.

Size Limitations in NTFS and FAT File Systems

Each file system supports a maximum volume size, file size, and number of files per volume. Because FAT16 and FAT32 volumes are limited to 4 GB and 32 GB respectively, you must use NTFS to create volumes larger than 32 GB. If you use FAT16 or FAT32 in computers that start multiple operating systems, you must note the following size limitations:

  • FAT volumes smaller than 16 MB are formatted as FAT12.

  • FAT16 volumes larger than 2 GB are not accessible from computers running MS-DOS, Windows 95, Windows 98, Windows Me, and many other operating systems. This limitation occurs because these operating systems do not support cluster sizes larger than 32 KB, which results in the 2 GB limit.

  • In theory, FAT32 volumes can be about 8 terabytes; however, the maximum FAT32 volume size that Windows XP Professional can format is 32 GB. Therefore, you must use NTFS to format volumes larger than 32 GB. However, Windows XP Professional can read and write to larger FAT32 volumes formatted by other operating systems.

  • If you create multidisk volumes such as spanned or striped volumes, the amount of space used on each disk is applied to the total size of the volume. Therefore, to create a multidisk volume that is larger than 32 GB, you must use NTFS.

For more information about FAT16 and FAT32, see FAT File System later in this chapter.

Maximum Sizes on NTFS Volumes

In theory, the maximum NTFS volume size is 264 clusters minus 1 cluster. However, the maximum NTFS volume size as implemented in Windows XP Professional is 232 clusters minus 1 cluster. For example, using 64-KB clusters, the maximum NTFS volume size is 256 terabytes minus 64 KB. Using the default cluster size of 4 KB, the maximum NTFS volume size is 16 terabytes minus 4 KB.

Because partition tables on master boot record (MBR) disks only support partition sizes up to 2 terabytes, you must use dynamic volumes to create NTFS volumes over 2 terabytes. Windows XP Professional manages dynamic volumes in a special database instead of in the partition table, so dynamic volumes are not subject to the 2 terabyte physical limit imposed by the partition table. Therefore, dynamic NTFS volumes can be as large as the maximum volume size supported by NTFS.

Itanium-based computers that use GUID partition table (GPT) disks also support NTFS volumes larger than 2 terabytes.

Note 

If you use large numbers of files in an NTFS folder (300,000 or more), disable short-file name generation, especially if the first six characters of the long file names are similar. For more information, see Optimizing NTFS Performance later in this chapter.

Table 13-5 lists NTFS size limits.

Table 13-5: NTFS Size Limits

Description

Limit

Maximum file size

Theory: 16 exabytes minus 1 KB (264 bytes minus 1 KB)

Implementation: 16 terabytes minus 64 KB (244 bytes minus 64 KB)

Maximum volume size

Theory: 264 clusters minus 1 cluster

Implementation: 256 terabytes minus 64 KB (232 clusters minus 1 cluster)

Files per volume

4,294,967,295 (232 minus 1 file)

Maximum Sizes on FAT32 Volumes

A FAT32 volume must have a minimum of 65,527 clusters. Windows XP Professional can format FAT32 volumes up to 32 GB, but it can mount larger FAT32 volumes created by other operating systems. Table 13-6 lists FAT32 size limits.

Table 13-6: FAT32 Size Limits

Description

Limit

Maximum file size

4 GB minus 1 byte (232 bytes minus 1 byte)

Maximum volume size

32 GB (implementation)

Files per volume

4,177,920

Maximum number of files and subfolders within a single folder

65,534 (The use of long file names can significantly reduce the number of available files and subfolders within a folder.)

Maximum Sizes on FAT16 Volumes

FAT16 supports a maximum of 65,524 clusters per volume. Table 13-7 lists FAT16 size limits.

Table 13-7: FAT16 Size Limits

Description

Limit

Maximum file size

4 GB minus 1 byte (232 bytes minus 1 byte)

Maximum volume size

4 GB

Files per volume

Approximately 65,536 (216 files)

Maximum number of files and folders within the root folder

512 (Long file names can reduce the number of available files and folders in the root folder.)

Formatting a Volume

You choose a file system when you format a volume. During the format, Windows XP Professional places key file system structures on the volume. These structures include the boot sector, the file allocation table (for FAT volumes), and the master file table (for NTFS volumes). Depending on the program you use to format a volume, you can also choose one or more of the following formatting options.

Volume label

Specifies the name of the volume using up to 11 characters for FAT volumes and 32 characters for NTFS volumes. Volume labels make it easy to identify volumes when you view them in Microsoft Windows Explorer, My Computer, and Disk Management.

Quick format

Creates the file system structure on the volume without verifying the integrity of every sector in the volume, which increases the formatting speed. If the volume is already formatted and you are sure the disk is not damaged, you can use this option. If quick format fails, perform the format again without using quick format. A full format identifies and tracks bad sectors so that they are not used for storing data.

Note 

You must use the quick format option if you format a volume created on a third-party hardware-based RAID array that supports pre-allocating space for future use even though the physical disks do not have this space available. In this case, if you do not choose the quick format option, the format does not complete because Windows XP Professional cannot read every sector on the disk.

Enable compression

Compresses all files in the NTFS volume. For more information about compression, see File Compression later in this chapter.

Allocation unit (cluster) size

Specifies the cluster size to be used when the volume is formatted. Use the default size unless you want to choose a different cluster size for performance reasons. For more information about the impact of cluster sizes on performance, see Optimizing NTFS Performance later in this chapter.

The available formatting options vary according to the program you use to format the volume. Table 13-8 describes the programs that you can use to format a volume as well as the available options for each program.

Table 13-8: Options Available When You Format a Volume

Format Option

Where the Option Is Available

 

Setup

My Computer or Windows Explorer

Disk Management

Format Command

Volume label

No option to create a volume label.

Available for all volumes.

Available for all volumes.

Use the /v:label parameter to specify the volume label.

Quick format

Available for all volumes.

Available for all volumes.

Available for all volumes.

Use the /q parameter to specify the quick format option.

Enable compression

No option to compress the volume.

Available for NTFS volumes.

Available for NTFS volumes.

Use the /c parameter to enable compression for NTFS volumes.

Allocation unit (cluster) size

Uses the default cluster size only.

Offers default cluster sizes for FAT volumes and clusters sizes up to 4 KB for NTFS volumes.

Offers all available cluster sizes.

Use the /a:size parameter to specify the cluster size.

When you format a volume during Windows XP Professional Setup, you can choose between NTFS and FAT. The version of FAT that Setup uses depends on the size of the volume. For volumes smaller than 2 GB (2048 MB), Setup uses FAT16. For volumes 2 GB or larger, Setup uses FAT32. For volumes 32 GB or larger, Setup uses NTFS and does not offer FAT.

Disk Management requires you to format volumes on dynamic disks and GPT disks as NTFS. Use the format command to format these volumes as FAT or FAT32. For more information about dynamic disks and GPT disks, see Disk Management in this book.

Note 

The format command is also available in Recovery Console. For more information about using Recovery Console, see Tools for Troubleshooting in this book.

You cannot format a volume that contains the paging file. Disk Management disables the Format menu command for paging file volumes. My Computer, Windows Explorer, and the format command display an error message when you try to format a paging file volume. You must move or delete the paging file before you can format the volume. For more information about identifying the volume that contains the paging file, see Disk Management in this book.




Microsoft Windows XP Professional Resource Kit 2003
Microsoft Windows XP Professional Resource Kit 2003
ISBN: N/A
EAN: N/A
Year: 2005
Pages: 338
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