1. NT Disks and Filesystems

administrating filesystems include
- making files and directories available to local and domain users
- monitoring and managing finite disk resources
- protecting against file corruption by establishing a well planned backup schedule
- ensuring data confidentiality by limiting file and system access
- connecting new storage when required

2. Making physical disks available

install and configure the hardware
partition the disk, into one or more logical independent pieces
creating the filesystems on each partition, called formatting in the windows world
adding files and directories to the new filesystem
specifying access permissions for these files and directories
enabling network access (sharing) for some or all of the filesystem

3. Managing disk partitions

traditionally PC disk partitions are of two types:
- primary partitions
- extended partitions
maximum of 4 primary partitions
extended partitions can be subdivided into units
- known as logical drives
drive letters are assigned to Windows NT partitions

4. Drive letters

drive letters assigned first to primary partitions
- then to extended and logical drives

5. PartitionMagic

is a powerful and flexible disk administration tool
it allows:
- resizing existing partitions
- moving a partition to a new location on the same disk
- copying a partition to a different disk
- changing the partition type
- hiding a partition
  - marks it as inaccessible

6. NTFS filesystem features

incorporates normal features of modern filesystems and has:
journaling
- before a change is made to the filesystem it is first recorded in a designated log file
  - implemented as a circular buffer and reused as necessary
- on reboot the filesystem structure is synchronised with the log file
- even after power loss the filesystem is returned to a consistent state
  - might incur some data loss
enhanced file security
- NTFS supports discretionary access control (DAC)
  - allows permitted and forbidden access to be specified in detail

7. NTFS filesystem features

lazy write scheme
- disk writes performed to a cache in memory rather than to a hard disk
- cache periodically written to the disk in background
  - technique has been around in Computer Science for at least 30 years!
```
ntsync
```
is a small free utility which flushes the cache
mirrored master file table and boot sector
- stores a second copy of the above in the middle of the disk

8. Managing filesystems

filesystems can be created via the disk administrators Tools->Format menu
alternatively you can use the command line program format, which has the following syntax:
```
format [/fs:ntfs] [/V:label] [/C] [/A:n] x:
```
- where x: is the drive
- /C for compression
- /A for allocation units
```
format /C /fs:ntfs /V:user e:
```
- formats partition e:, named user, it will utilise compression

9. NTFS Features: Compression

compression can be specified for
- individual files
- directories
- complete filesystems
if compression is not enabled for the filesystem
- can enable it for a directory
```
compact [/C | /U] [options] [files]
```
- /C compressed
- /U uncompress
- options include:
  - /S recursive
  - /I ignore errors
  - /Q terse output

10. Compact example

```
compact /C /S Books
```
which marks all subdirectories and files below Books as compressed

11. Mounting and checking filesystems

mounting is the process by which a filesystem is made available to the system
on Windows NT all local filesystems are mounted automatically at boot time
- might want to make a filesystem unavailable
- could use a public domain utility: unmount
```
unmount g:
```
umount will fail if there are any references to this filesystem
package also contains a mnt program for the reverse

12. Checking filesystems

chkdsk /f g:
The type of the file system is NTFS.
Chkdsk cannot run because the volume is in
use by another process. Would you like to
schedule this volume to be checked the
next time the system restarts? (Y/N) Y

/f checks and repairs any problems

13. Network Filesystem Access via Shares

making a filesystem available to other computers is known as sharing in NT
- a filesystem which is available to others is known as a share
any directory or folder can be shared
- files and subdirectories within them etc become available to network users
- you can disable this, by protecting lower level directories with access lists
protect via:
- user lists
- restricting number of users

14. Sharing command (on the server)

net share ntreskit=e:\ntreskit \
    /users:25 /remark:"Server Res Kit v4"

the directory ntreskit on drive e:
- number of simultaneous users is 25
- the comment string: Server Res Kit v4

15. Sharing command (on the server)

net share
can be used to modify the properties of an existing share
```
net share ntreskit /users:unlimited
```
- removes the upper limit of 25 users on ntreskit
  - note that we refer to ntreskit not e:\ntreskit
```
net share ntreskit /delete
```
- stops ntreskit from being shared at all

16. Sharing command (on the client)

to import a shared filesystem on a client can either use the GUI or command line
in a GUI or application you can reference the share via:
```
\\lucy\ntreskit
```
from the command line
```
net use g: \\lucy\ntreskit
```
- from now on g: references the ntnetkit

17. Persistent drive settings

may want shares to become active when a user logs in
- may want to access shares via a user account, privilege
allows us to manipulate the shares and then make the system remember the shares so that when we log in the environment is preserved

net use k: \\lucy\cygwin /user:hacker *
           /persistent:yes

means that the share cygwin is imported from server lucy and connected to the client as a user hacker
- hacker will be asked for their password

18. Persistent drive settings

are disabled by default
to make all existing drive mapping persistent, type:
```
net use /persistent:yes
```
to umount a share on a client:
```
net use k: /delete
```

19. net share

a server command
it is a good idea to type
```
net share
```
which displays all the shares the server is exporting

20. net use

a client command
```
net use
```
will list all the shared resources imported from a server onto the current client

Index

1. NT Disks and Filesystems
2. Making physical disks available
3. Managing disk partitions
4. Drive letters
5. PartitionMagic
6. NTFS filesystem features
7. NTFS filesystem features
8. Managing filesystems
9. NTFS Features: Compression
10. Compact example
11. Mounting and checking filesystems
12. Checking filesystems
13. Network Filesystem Access via Shares
14. Sharing command (on the server)
15. Sharing command (on the server)
16. Sharing command (on the client)
17. Persistent drive settings
18. Persistent drive settings
19. net share
20. net use
Index

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