LAN 1 Chapter 10

Chapter 10
Lecture Outline
Proper management of storage media and timely recovery from disk
failures are critical in the day-to-day operations of a network. 
Things happen that are out of the control of even the most experienced
network operators.  Windows 2000 Server has built-in methods of
reducing the down time associated with the inevitable catastrophic
failures that may call the typical network administrator into work at
2:00 A.M.
I.      Monitor, Configure, and Troubleshoot Disks and Volumes
A.      Basic Storage
1.      Windows 2000 Server will configure storage devices as basic disks
by default.

2.      Basic storage uses the traditional method of dividing physical
disks into primary partitions and extended partitions with logical
drives.

3.      Provides backward compatibility with DOS, Windows 9x, and Windows
NT.

4.      Partitioning Basic Disks
a.      A Windows 2000 basic disk can contain between one and four
partitions.
b.      Each partition can be formatted with any file system. (NTFS, FAT16,
FAT32, etc.)
c.      Dividing a hard disk into partitions allows you to create a
multi-boot configuration with operating systems that use different
file systems.
d.      Windows 2000 allows you to create, delete, or change the partition
structures on basic disks
e.      Windows 2000 will recognize partitions created by older operating
systems, such as DOS, Windows 9x, and Windows NT.

5.      Primary Partitions
a.      There is a maximum of four primary partitions per physical hard
disk.
b.      Only one can be made active in order to boot the system.

6.      Extended Partitions
a.      Extended partitions do not represent one drive, rather they provide
a container for logical drives.
b.      Any number of logical drives can be created in an extended
partition.

7.      Set Types on Basic Storage
a.      Basic disks can be grouped into sets based on network needs.
i.      Stripe Set
ii.     Mirror Set
iii.    Volume Set.
b.      Basic disk sets will be recognized by Windows 2000 Server if they
were created on an earlier version of NT.
c.      Volume Sets
i.      Not fault tolerant
ii.     Requires at least 1 physical disk, but can be created on up to 32
disks
iii.    Useful when using "leftover" space from partitioning schemes
iv.     Figure 10-3 on page 481 demonstrates one volume spanning four
disks.
d.      Mirror Sets (RAID Level 1)
i.      Fault tolerant
ii.     Requires two physical disks
iii.    Creates a mirror, or exact copy, of a partition that may include
sensitive information or the operating system files. iv.        A more
reliable form of mirroring is called duplexing.  This is the same as
mirroring, except that two separate controllers are used as well.
iv.     Mirroring slows the system down when writing to the hard drive.
v.      It can be migrated from NT 4.0 to Windows 2000 Server.
e.      Stripe Sets (RAID Level 0)
i.      Not fault tolerant
ii.     The term "striping" refers to the writing of data across separate
physical disks.
iii.    Each file is broken into 64KB blocks, after which each block is
evenly and alternately saved to the disks in the stripe set.
iv.     RAID Level 0 requires a minimum of 2 physical disks.  
v.      It also requires all partitions on the drives to be equal in size.
vi.     Figure 10-4 on page 482 demonstrates the process of writing to a
stripe set.
f.      Stripe Set with Parity (RAID Level 5)
i.      Fault tolerant
ii.     Requires at least three hard disks
iii.    Information is written to the drive when stored, and also written
into parity.
iv.     If information is lost, then it can be reconstructed with the
parity information from the other drives.
v.      Figure 10-5 on page 483 illustrates the interleaving of data and
parity information across disks.
B.      Dynamic Storage (very difficult to recover from when a failure
happens requiring a  reinstall, use Hardware RAID and basic disk
instead of Dynamic disk The 2000 installer does not see dynamic disk
until Windows is already installed so a reinstall will require wiping
out all partitions and starting over.)

1.      Windows 2000 supports a new storage type, called dynamic disk. 
This storage type is unique to Windows 2000, and cannot be used by
other operating systems.
a.      Partitions are now called volumes.
b.      Dynamic disks allow you to simply create volume after volume, with
no limit on the number or type that can exist on a single disk (you
are limited only by the capacity of the disk itself).
c.      Information about volume number and type is stored in a disk
management database on the last 1MB of the disk.
d.      Each disk's management database contains the volume information of
all the other disks, up to approximately 512 disks.
e.      If the database on any disk becomes lost or corrupt, the
information is automatically restored by the other disks.
f.      The only limitation is that the drives and their databases must
reside on the same physical computer.
g.      Dynamic disks are not supported by removable media or laptops.

2.      Volume Types on Dynamic Disks
a.      Simple Volume
i.      Not fault tolerant
ii.     Simple volume is a single volume that does not span more than one
physical disk.
iii.    Nor does it provide improved drive performance, extra capacity,
or fault tolerance.
iv.     It's similar to partitions on a pre-Windows 2000 machine.
b.      Spanned Volume
i.      Not fault tolerant
ii.     A spanned volume is a volume that's assigned the same drive
letter, and which spans several drives and partitions.
iii.    It is created from "leftover space" of varying sizes.
iv.     Similar to a Volume Set.
c.      Mirrored Volume
i.      Fault tolerant
ii.     Like basic disks, dynamic disks can also be mirrored, and are
called mirrored volumes.
iii.    A continuous and automatic backup of all data in a mirrored
volume is saved to a separate disk to provide fault tolerance.
iv.     You cannot mirror a spanned or striped volume.
d.      Striped Volume
i.      Not fault tolerant
ii.     A striped volume is the dynamic storage equivalent of a basic
stripe set in which data is written across more than one physical disk
(up to 32 disks) to improve drive performance and increase drive
capacity.
e.      RAID-5 Volume
i.      Fault tolerant
ii.     A RAID-5 volume on a dynamic drive provides disk striping with
parity, and is similar to a basic stripe set with parity.
iii.    RAID-5 requires 3 or more physical disks, up to a total of 32.  
iv.     Each partition in the set must be the exact same size.

3.      Upgrading Basic Storage to Dynamic Storage
a.      Exercise 10-1 on page 487 demonstrates how to upgrade from a basic
disk to a dynamic disk.  It is not possible to upgrade to a dynamic
disk unless the 1MB empty space requirement is met. (This is why when
using Windows 2000/XP/2003 disk partitioning utilities they leave
around 1~8MB of free space, you should have seen this free space
already in some of the installation labs)
b.      Upgrading to dynamic storage preserves any existing data.
c.      Reverting Back to Basic Disks
i.      Dynamic disks are limited in that they are not available to legacy
operating systems.  This includes those that connect across a network.
ii.     This, however, is correctable.  It is possible to revert back to a
basic disk configuration using the Disk Management utility.
iii.    Data contained on the dynamic volumes cannot be retained when
reverted back to basic.  All dynamic volumes must be deleted prior to
reverting.
C.      File Systems

1.      Once a partition, set, or volume is created, it must be formatted
with a file system before it can store data.  Supported file systems
include:
a.      FAT16
b.      FAT32
c.      NTFS
d.      NTFS 5

2.      FAT16 (File Allocation Table)
a.      Limited to 2 gigabytes per single partition
b.      Is inefficient when handling larger volume sizes
c.      Is necessary to support legacy operating systems like DOS and
Win3.11
d.      Offers no security other than share level permissions

3.      FAT32
a.      Updated version of FAT16
b.      Appeared with Windows 95 OSR-2, and is deployed with Windows 98
c.      Can be partitioned up to 2 terabytes (only 32GB with the 2000 disk
utility larger partitions must be created with the DOS fdisk utility)
d.      NOT accessible by Windows 3.11, DOS, and NT 4.0
e.      Offers no security other than share level permissions

4.      NTFS (New Technology File System)
a.      Provides file and directory-level security
b.      Offers native file compression 
c.      Allows fault tolerance configurations
d.      Can be partitioned up to 2 terabytes
e.      Offers security down to the file level
f.      NTFS is the legacy file system associated with NT 4.0.

5.      NTFS v5.0
a.      Offers the same features as NTFS
b.      Supports the encrypting file system (described in Chapter 12)
c.      Sparse file support enables Windows 2000 to use partial clusters,
thus reducing wasted space on the drive.
d.      Disk quotas are now available without the use of third party
software.

6.      Converting to NTFS
a.      When Server 2000 is installed, all existing NTFS volumes are
upgraded to NTFS v5.0.
b.      FAT16 and FAT32 volumes can also be upgraded, without data loss.
c.      Conversion can be done at any time using the Convert.exe [drive:]
/fs:ntfs
d.      NTFS drives that are converted cannot be reverted without data
loss.
D.      The Disk Management Tool

1.      Allows you to perform a large number of disk management tasks in an
easy-to-use interface.
a.      The upper-right-hand pane displays each partition or volume in the
system.
b.      Information about each physical disk, and the partitions or volumes
on each is then displayed.
c.      Layout makes it easy to determine which volumes belong to which
physical disks.
d.      Conduct Exercise 10-2 on page 492. 

II.     Configure Data Compression
A.      The NTFS file system includes native data compression (no external
compression utility is required).
Note: It is the NTFS file system that supports compression.  Windows
2000 machines under FAT and FAT32 cannot utilize native compression.
B.      Conduct Exercise 10-3 on page 495 to demonstrate how to compress
volumes.

III.    Monitor and Configure Disk Quotas
A.      Introduction

1.      Windows 2000 Server allows administrators to assign drive space
limits (quotas) to all users of a system.

2.      Quotas can be set only on entire volumes, and not on individual
files or folders.

3.      Users can be given quotas on a single volume.  Such as 50MB for all
users in the Accountants group for drive D.

4.      Quotas can be given to volumes that span physical drives.

5.      Determining a user's quota is based on ownership of the files on
the volume.
B.      Setting, Assigning, and Configuring Disk Quotas
1.      Conduct Exercise 10-4 on page 498: Assigning Quotas.
2.      Conduct Exercise 10-5 on page 499: Creating New Quota Entries.
C.      Disk Quota and Compression
1.      Disk quotas are not affected by file, folder, or volume
compression.
2.      Compression of files does not allow more information to be placed
on a volume with quotas.
a.      For example: A user with a 40MB quota, 39 of which are used, will
not be able to save a 1.5MB file onto the volume, even though he or
she compresses it to 750KB.
b.      The original size is the criteria that the quota is concerned with,
not the compressed size.

IV.     Recovering from Disk Failure
A.      Implementing fault-tolerant volumes requires that they be
preexistent or that the drives be converted to dynamic drives.

1.      Creating mirrored volumes requires two physical disks.  Select
Mirrored Volume in the Create Volume Wizard.

2.      Creating a RAID-5 volume requires a minimum of three physical
disks.  Choose RAID-5 in the Create Volume Wizard.
B.      Recovering a Failed Mirrored Volume
The Disk Management window includes status descriptions for each disk
and volume in the system; a method that will allow a network
administrator to locate a problem physical disk.

1.      Offline or Missing Disks
a.      Since a mirror has to have two physical disks, it is possible that
one may become faulty or fail, causing the mirror to go offline.
b.      The Disk Management tool can investigate why the disk is offline.
c.      If the mirror is in an offline condition and the disks are still
visible in the Disk Management tool, right-click the offline drive and
select Regenerate.
d.      This method is designed to handle only minor disk issues.  
i.      Corrupt Data
ii.     Intermittent Accessibility
e.      If the disk cannot be repaired using this method, it must be
replaced, and the mirrored volume must be re-created.
f.      Conduct Exercise 10-6 on page 503.
C.      Recovering a Failed RAID-5
Since RAID-5 offers fault tolerance, drives in the array can be
regenerated from the parity information that is contained on the disks
in the set.

1.      Offline or Missing Disk 
a.      Must be returned to an online state before the RAID-5 volume can be
accessed.  A RAID-5 volume may be in an online state even if one
member of the stripe set has failed.
b.      Try reactivating the disk.  If this doesn't work, repair the disk,
then reactivate it.
c.      The volume's status should automatically change to Regenerating,
then back to Healthy.