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The current version of NTFS is 4.0, Ive not really noticed any great changes since
its first incarnation in Windows NT 3.1 and so we can assume its just gone up by 1
with each NT release, NTFS 1 in 3.1, NTFS 2 in 3.5, NTFS 3 in 3.51 and now NTFS 4 in 4.0.
Microsoft has made quite a big fuss about NTFS 5.0; is this just an increment to the file
system version to match the OS version? Well no. For the first time the jump in the file
system number represents a huge leap for the file system functionality.
NTFS was a totally new file system, not just an enhancement to FAT, and offers no
backwards compatibility for operating systems that only understand FAT,
operating systems such as Windows 95, Windows 98 and DOS cannot read NTFS drives so if you
want to share a disk between operating systems keep it FAT. There are utilities that exist
which enable you to read NTFS from outside NT such as NTFSDos from www.sysinternals.com.
Security was a major addition to NTFS. In FAT you could hide files, but anyone could
unhide them with the attrib command or view them by using the dir /ah command.
With computers becoming linked together and more than one person operating a computer, a
method was needed to secure files so that only the intended could view/modify files. With
NTFS you can assign exact privileges for every user/group to every file and folder
providing a secure environment so that only those with the correct permissions can gain
access.
As we mentioned above, utilities exist which can access NTFS volumes from outside of the
operating system and bypass the NTFS security. More and more people use portables, often
with sensitive data on them, and NTFS is no longer secure enough. NTFS 5.0 introduces
something to combat this problem.
Dynamic disks
The current volume structure has been carried over from early DOS days; you have a primary
partition, and extended partition with a number of logical volumes. Windows 2000 throws
this away for a more sophisticated approach. It introduces the idea of a dynamic disk
needed for fault tolerant configurations. Dynamic disks are used by the Logical Disk
Manager (LDM) which is different from the Disk Management snap-in. Dynamic disks contain
only dynamic volumes, there is no concept of a primary partition, logical volume etc.
Dynamic disks are needed in Windows 2000 for the creation of mirrored, spanned, striped or
striped with parity sets, however, existing sets created under Windows NT 4.0 are
supported on basic disks in Windows 2000. Dynamic volumes can also be resized by adding
extra space from unpartioned space and used without a reboot.
Only the Windows 2000 operating system understands dynamic disks, Windows 9x, Windows NT
4.0 etc all cannot read dynamic disks and if you multi-boot with any of these do NOT
upgrade to dynamic disks. Its possible to convert a basic disk to a dynamic disk
(but this is a one way transformation). Perform the following:
- Start Computer Manager
- Expand Storage - Disk Management
- Right click on the disk and select Upgrade to Dynamic
DiskRight click on the disk and select Upgrade to Dynamic Disk.
- Select the disks to upgrade and click OK.
- A summary will be displayed.
- Click Upgrade.
- Click Yes to the confirmation.
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Converting Basic disks to Dynamic
disks doesnt require reboots, however, any volumes contained on them after the
conversion will generate a popup that basically says a re-boot is necessary before the
volumes can be used. Its safe to say no to the reboot, wait until all the volumes
are identified and all the popups go away, and then perform a single re-boot.
When you upgrade from basic to dynamic, any existing partitions become simple volumes. Any
existing mirrored, striped or spanned volumes sets created with NT 4.0 become dynamic
mirrored, striped or spanned volumes respectively. If you get a message that says you are
out of space then you may not have enough unallocated free space at the end of the disk
for the private region database that Dynamic disks use to keep volume information. To be
Dynamic it needs about 1 MB of this space, sometimes the space is not visible to the user
in the GUI, but it is still there. You may not have the space if the partition(s) on the
disk take up the entire disk and were created with Setup, an earlier version of NT or
another OS. If partitions are created within Windows 2000, the space is reserved,
partitions created with Setup will reserve the space in a later release. To undo this
conversion run you should backup any data on the disk you wish to preserve, and then
delete all partitions - that should activate the menu choice "Revert to Basic
Disk", the entire disk HAS to be unallocated or free space.
The removal of choice
When you install Windows 2000 ALL NTFS partitions will be upgraded to NTFS 5.0. Yes, ANY
and ALL NTFS volumes Windows 2000 sees including removable media are
automatically converted to V5.0 on the fly when Windows 2000 mounts them so make sure if
you move disks between machines they are all Windows 2000 or if using Windows NT 4.0 have
Service Pack 4 or above installed.
Service Pack 4 for Windows NT 4.0 has an updated NTFS.SYS which can read NTFS 5.0
partitions so apply this to any systems that need to read Windows 2000 NTFS 5.0 partitions
and make sure you do this BEFORE installing Windows 2000. You can, if you wish, only copy
over the NTFS.SYS if you dont want to apply Service Pack 4 or above (but you need to
anyway to be Y2K compliant, of course if youre reading this now and youve not
deployed Service Pack 4, panic!) By default (you can override using advanced option
button) on server installations the boot partition will be upgraded to NTFS if youre
not in a dual boot environment, yep thats right it automatically upgrades from FAT
to NTFS.
Encrypted File System
I mentioned problems with NTFSs security, that tools exist which require console
level access to the machine and require booting off a special disk or CD-ROM, but with
more and more mobile computers something extra is needed for sensitive data that is
carried with us every day. EFS uses a public/private key encryption scheme and the
CryptoAPI architecture. EFS can use any symmetric encryption algorithm to encrypt files,
however the initial release only uses DES. 128-bit keys are used in North America, 40-bit
internationally. No preparation is needed to encrypt files and the first time a user
encrypts a file an encryption certificate for the user and a private key are automatically
created. If encrypted files are moved they stay encrypted, if users add files to an
encrypted folder the new files are automatically encrypted. There is no need to decrypt a
file before use; the operating system automatically handles this for you in a secure
manner. In the event of a users private key being lost (either by reinstallation or
new user creation), the EFS recovery agent can decrypt the files. Encrypted files cannot
be read from outside Windows 2000 or within Windows 2000 without the required certificate
needed to decrypt.
If youre using Windows 2000 professional in a 4.0-based domain, you will not be able
to use the encrypted file system, as a machine in a domain uses the domain policy for
recovery if the domain does not support EFS (such as a 3.51 or 4.0 domain). To get around
this perform the following:
- Remove the Windows 2000 computer from the Windows NT 4.0 domain.
- From the command prompt, type:
secedit /refreshpolicy machine_policy /enforce
- Rejoin the Windows 2000 computer to the Windows NT 4.0 domain.
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Reparse Points
Much of the new Windows 2000 file system enhancements are possible thanks to reparse
points which basically provide a hook into the file system and allow
extensions to the storage subsystem without the need for proprietary code to be written.
Reparse points are actually special file system objects which have a special attribute
that activates extra functionality in the storage subsystem. Any file or folder can have a
reparse point, meaning a single path can trigger multiple portions of extended
functionality.
Directory Junctions
These just allow you to join folders together so you can map a directory to any local
target directory. Imagine you had three folders, c:\folder1, c:\folder2 and c:\documents.
Its possible to create a directory junction so c:\documents appears as a
subdirectory of the other two folders resulting in c:\folder1\documents and
c:\folder2\documents. Sadly, to create a directory junction you will need to write a
utility since none is supplied.
On first view, directory junctions and the Distributed File System perform some of the
same roles, as they both give the appearance of a single directory tree which actually
consists of multiple, distributed folders, however there are differences:
- DFS utilises the Active Directory to store its information.
Thanks to its Active Directory root DFS can provide fault tolerance and load balancing,
directory junctions cannot provide either of these although in a local context its
not as necessary.
- DFS is more geared to merging network resources into a single
namespace where as directory junctions only link local machine resources.
- DFS can work using multiple file systems but directory
junctions rely on NTFS 5.0.
- DFS requires a client piece, directory junctions dont.
Mount Points
Mount points are similar to junction points except they allow only the root of a volume to
be mounted as a folder and are created using reparse points, thus the NTFS 5.0
requirement. Mount points are useful for increasing a drives size
without disturbing it. For instance, you could create a mount point to drive d: as
c:\documents thus seeming to increase the size available on C:. To create a mount point
just perform the following:
- Start the Computer Management MMC snap-in (Start
Programs Administrative Tools Computer Management)
- Expand the Storage branch and select Disk Management
- Right click on the volume you want to create as a mount point and
select Change Drive Letter and Path
- Click Add
<ntfs5-1.tif>
- Select a new folder for the folder to be mounted as. If
you click browse it will only show NTFS 5.0 volumes.
- Click OK
- <ntfs5-2.tif> Here we are going to map drive G: as d:\data
drive
If you now look in Explorer you will see your new mount point, but
instead of a folder icon it will be a drive icon. Notice the contents of the d:\data drive
folder are the same as those shown under g:
Disk Quotas
Windows 2000 introduces limited quota support which enables you to configure quota limits
on a per user/per volume basis. You cant set a quota over multiple volumes.Quotas
are on file size and even if files are compressed you still only get the MB of amount of
the files. If you had a 5 MB quota and compressed your 5 MB of files using NTFS
compression you would have used all your quota.Quota support is only available on NTFS 5.0
volumes and is enabled as follows:
- Start Explorer
- Right click on the volume and select properties
- Check the Enable quota management box
You can set default options for new users and also set the actions
to take if quota is exceeded, either deny disk space or allow them to carry on. There are
also various logging options, either when a user exceeds their warning level or when they
exceed their actual quota.
A warning will be given. Click OK. The quota process will now check
the volume and build up a list of current disk usage. The new features are certainly
welcome, in particular the Encrypted File System and user quotas are a good start but
there are many other third party alternatives to the quota problem which make the built-in
NTFS 5.0 solution only good for very small environments. I think the option of the upgrade
from NTFS 4.0 to NTFS 5.0 would have been good but with so many Windows 2000 functions
relying on NTFS 5.0 I can see why.
One final word though, if you play with the Encrypted File System remember its all
certificate based, if you reinstall Windows 2000 and youre not in a domain
youll lose the certificate to decrypt and access to your work! I know one unhappy
person who lost a lot of work after encrypting his folder and reinstalling the OS. New
functions are good but make sure you understand them before using! Check the NT FAQ, www.ntfaq.com for information on backing up the EFS
recovery certificate.
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