Windows 2000  File Systems

Introduction to file systems

• NTFS  has a number of advanced features that make it a superior filing system to other Microsoft filing system.

• The features of NTFS  include security, fault tolerance, advanced searching , sparse files , disk quotas, file compression, encrypted file system etc.

Key Topics

Partitioning  the Drive Windows Professional  Volume Filing  systems File Allocation Table FAT and FAT32 NTFS  Filing  System FAT 32 V NTFS

NTFS  Logging of files Disk Quotas Converting to NTFS File Compression  in Windows Encrypted  File System Recovery Agent

Partitioning  the Drive

• FDISK.EXE  is a DOS  or Windows 9x utility, which can be used to partition your hard drive

• There are two possible DOS  partitions in a basic disk , The primary partition  and extended partition which contains logical drives.

• All partitions of DOS  must exist within the primary and extended partitions .

Windows Professional  FAT Partition

• Windows 2000  Professional supports partitions and installs itself on the partition with a FAT filing system if the partitions exist prior to the installation  of Windows Professional .

Windows Professional  Volumes

• If a drive has not been partitioned prior to windows professional installation , Windows professional will attempt to create a volume during the installation.

File Systems

• Windows 2000  supports all previous Microsoft partition filing systems.

• Windows 2000  supports FAT, FAT32 , NTFS , and the new NTFS 5 introduced with windows 2000.

• Some of the new filing features of windows 2000 can only be attained on NTFS  5.

File Allocation Table (FAT)

• The simplest way of organizing the storage space on the hard drive  when dealing with files  and folders

• FAT contains a table of content listing the cluster location of all files  recorded on the storage medium

• FAT 16 was developed for DOS  version 3 and above supporting partition sizes of 2GB and a hard drive  size of 4GB 

File Allocation Table (FAT32 )

• FAT32  supports drive sizes of up to 2 Terabytes TB.

• Windows 2000  limits FAT32  to 32GB, which can be expanded with service packs.

• FAT 32 uses a more efficient way of saving files  reducing the cluster size to a uniform 4KB in small and large drives.

FAT32  Point Of Failure

• FAT32  is made more stable and less susceptible to a single point of failure then FAT by extending the boot records to include the backup of the critical data structure.

FAT V FAT32

• This is a table of comparison of cluster size change with volume size for FAT16  and FAT32  partitions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NTFS  File System Features

• NTFS  stands for New Technology File System.

• NTFS  supports File, Folder and Volume compression

• If something goes wrong during compression, individual files  are affected rather than regions on the disk since NTFS  compression is based on individual file compressions.

NTFS  File System

• NTFS  can support partition sizes up to 16 exabytes  (2⁶⁴ ) which uses uniform cluster sizes of 4KB .

• The backup of the boot sector performed on NTFS  is kept at the end of the volume.

• NTFS  ensures file recovery  and volume consistency using a new transaction logging and recovery technique.

NTFS  Searching

• Can set individual user and group  permissions  on files , folders  and shares on the volume.

• NTFS  uses a B-Tree  directory  structure that improves search performance  since it is the directory structure used in most databases .

FAT32  V NTFS

• This is a table of comparison of cluster size change with volume size for FAT32  and NTFS  volumes.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NTFS  Fault Tolerance

• NTFS  has a hot fix feature, which means that on every write  process, Windows 2000  verifies the file correctness by reading the file again.

• If the file has become corrupted, Windows 2000  will mark that region on the disk as bad and will rewrite the data in another data block.

NTFS  Logging Of Files

• Since NTFS  logs all filing system changes, if a power loss occurs while changes are being made and a read  or write  task is not completed, the task will be completed once power is restored.

NTFS  Contiguous Blocks

• NTFS  reduces the need for defragmentation because it always attempts to write  data in contiguous  blocks. 

NTFS  Security

• NTFS  has security built in as part of the filing system. When you format  your hard drive  with NTFS, its permissions  can be utilized which are list , read , write , read and execute , modify , full control

NTFS  Security  Module

• NTFS  security is explained in more depth within the windows 2000 security module .

Sparse  Files

• Sparse  files  are used by NTFS  for reducing disk space requirement for large files.

• Sparse  files  have an attribute  that allows the interpreter of the input /output  subsystem to allocate ranges of space only for data, which is 1, but not for 0.

• When streams of one and zero’s are stored, the ones are allocated where as the zero’s are unallocated.

• When sparse files  are read , the allocated data returns ones and the unallocated data returns zeros.

 

 

 

 

 

 

 

 

Other NTFS  Features

• Change  Journal:- A persistent log is created by a sparse stream which tracks file information  and changes on an NTFS  volume. The change journal can be used by applications , which need to track previous events on a volume such as incremental backup applications, and remote storage applications.

• Master File Table (MFT ): -All NTFS  volumes have an MFT which contains information  specific to all the files  on the NTFS volume including size, date and time of modification, permissions  etc.

Disk Quotas

• Administrators can constrain and monitor the quantity of space used on the storage devices  by all the users within an NTFS  5 partition or volume using windows2000.

Individual Disk Quotas

• This disk restriction tool can be defined as disk quotas and can be preset in quantity for all the users of the environment to a defined value or set differently for individual users.

 

Exercise(Adding Disk Quotas )

Double click on the my computer Right click on the NTFS  drive on your system From the drop down menu select the properties option by clicking on it From the volume properties window click on the quota tab On the quotas sheet choose check the enable quota management box Under the limit disk space to text box type a value that you want Under the set warning level to text box type a value 5MB less then the disk space value. Finally click on the OK button.

 

Converting To NTFS

• Windows 2000  provides a utility to convert  FAT to FAT32  or FAT/FAT32 to NTFS , which can ultimately results in the data on those partitions being lost.

Converting To NTFS  Without Data Loss

• You can convert  FAT to NTFS  without reformatting and loss of data on the partition by using the following command in command prompt

• Convert x: /FS:NTFS  /v

File Compression  In Windows 2000

• The compression of files  folders  and volumes is supported by windows 2000 only on NTFS  volumes.

Compression  Filter

• There exist a compression filter  driver , which decompresses the files  requested by a windows 2000 application or before being used by the application, and when the application closes, the filter recompresses the files again seamlessly.

• The filter is also activated when copying files  into compressed  folders  or copying files from a compressed folder.

File Compression  In Windows 2000

• Compressed files  can be viewed in a different color in Windows 2000  explorer.

• The NTFS  compression program is only functional on volumes with cluster sizes of 4KB.

• Any compression causes performance  degradation because the compression filter  needs to be activated on the files  of interest every time the file is required before the files can be used. 

Exercise(Compressing a folder)

Double click on the my computer Double click on the NTFS  drive Right click on a folder that needs to be compressed From the drop down menu click on the properties option. Under the general tab click on the advanced button On the advanced attributes window check the compress contents to save disk space check box.

 

Encrypted  File System (EFS )

• Encrypted  File System can be used on NTFS  using symmetric key encryption controlling access to files

• Symmetric key encryption  and public keys  can be used in Windows 2000  to encrypt files  and folders , only making them available to the owner of the files or folder seamlessly.

 

EFS  And Digital Certificates

• A digital certificate is issued to the file owner, which has public and private key components.

• Windows 2000  runs an automatic transparent decryption/encryption of files  for the owner of the files.

• Unauthorized users who try to access encrypted files  are denied access to those files. 

EFS  Utilities And Rules

• You can encrypt and decrypt your folders  using disk utilities or the command line tool Cipher to encrypt and decrypt files  and folders. 

• Encrypted  files  and folders  cannot be compressed .

• Windows 2000  on NTFS  volumes support the compression of only files  folders  and volumes.

• Compressed files  can be viewed in a different color in Windows 2000  explorer.

• The NTFS  compression program is only functional on volumes with cluster sizes of 4KB.

Recovery Agent In EFS

• If the owner of the encrypted files  is not available, then the private key of the recovery  agent can be used to decrypt the files.

• The default recovery  agent is either the administrator  of the machine or the domain administrator. 

Exercise (Encrypting a folder)

Double click on the my computer Double click on the NTFS  drive Right click on a folder that needs to be encrypted From the drop down menu click on the properties option. Under the general tab click on the advanced button On the advanced attributes window check the encrypt contents to secure data check box.

 

Questions

1. What are the features of NTFS? (Choose all that apply)

1. Efficient filing system

2. Can be used by DOS  

3. B-tree searching

4. Hot fixes built in

5. Can be used by windows98

2. What are the features of NTFS? (Choose all that apply)

1. More efficient the FAT32

2. More secure then FAT32

3. Clusters are an even 8KB

4. NTFS  logging

5. Clusters are an even 4KB

3. What are the features of NTFS? (Choose all that apply)

1. Supports sparse files

2. Support for drive compression

3. Support for file compression

4. Support for fast files

5. Support for analogue data

4. What are the features of NTFS? (Choose all that apply)

1. Support or EFS

2. Support for file compression

3. Support for disk quotas

4. Support for EFS  and file compression

5.  Support for EFS  or file compression

Answers

1.      A,C,D

2.      A,B,D,E

3.      A,C

4.      A,B,C,E