Windows 2003 Server

Chapter 6

Managing Disk and Data Storage


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Summary

At the end of this chapter you should be able to:

  • Understand concepts relating to disk management

  • Manage partitions and volumes on a Windows Server 2003 system

  • Understand the purpose of mounted drives and how to implement them

  • Understand the fault tolerant disk strategies natively supported in Windows Server 2003

  • Determine disk and volume status information and import foreign disks

  • Maintain disks on a Windows Server 2003 system using a variety of native utilities


Disk Management Concepts

Windows Server 2003 supports two types of data storage types.  The fist is basic disks, and the second is dynamic disks.

 

Basic Disks

Basic disks are what we are used to when partitioning hard drives.  You can have four primary partitions.  One of those primary partitions can be an extended partition which can contain logical drives.  Each partition is given a drive letter in Windows and can be formatted as FAT, FAT32, or NTFS.  Windows Server 2003 creates this type of drive by default.

 

In Windows Server 2003 you will see references to the boot partition and the system partition.  The system partition (system volume on dynamic disks) contains the boot files, for example Ntldr, Boot.ini, Ntdetect.com.  This must reside on a primary partition that is marked as active.  The boot partition (boot volume on dynamic disks) contains the \Windows folder.

 

Windows NT 4.0 supported Volume Sets and Strip Sets.  If you have upgraded from Windows NT 4.0 to Windows server 2003 any existing set will be supported.  You will not be allowed to create new sets, you will need to upgrade to dynamic disks and use volumes.

 

Note: There are a couple rules about disks in Windows Server 2003.

  • Basic disks use partitions.

  • Dynamic disks use Volumes.

  • A partition on a basic disk is known as a simple volume on a dynamic disk.

  • Volume sets from NT 4.0 = Spanned volumes on a dynamic disk.

  • Striped sets from NT 4.0 = Striped volumes on a dynamic disk.

  • Mirrored sets from NT 4.0 = Mirrored volumes on a dynamic disk.

  • Striped sets with parity from NT 4.0 = RAID-5 volume on a dynamic disk.

Dynamic Disks

Dynamic disks give you more options with your hard drive layout then basic disks.  They allow you to setup RAID volumes for fault tolerance and/or increased performance.  You can also extend NTFS partitions, reactivate a missing or offline disk, and change disk settings with requiring a restart.  Dynamic disks support the following volume types.

  • Simple Volume - A storage unit made from free space on one disk.  You can extended a simple volume to included more free space on the same drive.  You cannot extended the system or boot volumes. 

  • Spanned Volume - You can take a simple volume and expand it over multiple disks.  Once a simple volume crosses multiple disks, it is known as a spanned volume.  If one drive is lost in a spanned volume all the data is lost.

  • Mirrored Volume - A fault tolerant volume whose data is duplicated on two physical disks.  A mirrored volume cannot be extended.  This is also known as RAID-1.

  • Striped Volume - This is where your data is interleaved across two or more physical drives evenly.  This increases performance and spreads the work load across all drives.  This is also known as RAID-0, no fault tolerance.  This cannot be mirrored or extended.

  • A RAID-5 Volume - A fault tolerant volume whose data is striped across an array of three or more disks. Parity (a calculated value that can be used to reconstruct data after a failure) is also striped across the disk array. If a physical disk fails, the portion of the RAID-5 volume that was on that failed disk can be recreated from the remaining data and the parity. A RAID-5 volume cannot be mirrored or extended.


Managing Partitions and Volumes

The main tool used to manage disk properties is the Disk Management snap-in. 

 

LAB ACTIVITY - Do the lab on page 229. (10 Minutes)


Creating Partitions and Volumes

Lets look at the process of creating a partition, converting to dynamic disks and creating volumes.

 

LAB ACTIVITY - Do the lab on page 230. (5 Minutes)

LAB ACTIVITY - Do the lab on page 231. (5 Minutes)

LAB ACTIVITY - Do the lab on page 232. (5 Minutes)

LAB ACTIVITY - Do the lab on page 234. (5 Minutes)

LAB ACTIVITY - Do the lab on page 235. (5 Minutes)


Extended Volumes

Volumes in Windows Server 2003 can be extended, (unless they are the system or boot partition).  You can use the Disk Management snap-in or the DISKPART command line utility.

 

LAB ACTIVITY - Do the lab on page 235. (5 Minutes)


Mounted Drives

We are use to giving volumes or partitions drive letters, but Windows Server 2003 supports using an empty folder as mount point.  If you have to simple volumes on one drive you can have one be a C: drive and mount the other in C:\Data.  You can also mount removable media in a directory.

 

LAB ACTIVITY - Do the lab on page 237. (5 Minutes)


Fault Tolerant Drive Strategies

Windows Server 2003 supports software RAID.  Some of the RAID volumes were already discussed above, we will now go into more detail about RAID and the different levels.

 

RAID Levels

RAID

Details

Supported

0 Provides data striping (spreading out blocks of each file across multiple disk drives) but no redundancy. This improves performance but does not deliver fault tolerance. If one drive fails then all data in the array is lost.  Yes
1 Provides disk mirroring. Level 1 provides twice the read transaction rate of single disks and the same write transaction rate as single disks. Yes
2 Not a typical implementation and rarely used, Level 2 stripes data at the bit level rather than the block level. No
3 Provides byte-level striping with a dedicated parity disk. Level 3, which cannot service simultaneous multiple requests, also is rarely used. No
4 A commonly used implementation of RAID, Level 4 provides block-level striping (like Level 0) with a parity disk. If a data disk fails, the parity data is used to create a replacement disk. A disadvantage to Level 4 is that the parity disk can create write bottlenecks. No
5 Provides data striping at the byte level and also stripe error correction information. This results in excellent performance and good fault tolerance. Level 5 is one of the most popular implementations of RAID. Yes

 

Software RAID and Hardware RAID

Software RAID is implemented by Windows Server 2003, hardware RAID is implemented by your hardware controller.  Most servers use hardware RAID when configuring RAID.  If you setup a RAID 5 container using hardware RAID Windows Server 2003 will see it as one drive.  There are advantages to using hardware RAID.

  • Faster read and write response.

  • The ability to place the system and boot files on a RAID drive.

  • The ability to hot-swap drives.

  • More setup options.


Monitoring Disk Health and Improving Foreign Disks

Using the Disk Management snap-in you can check the status of your volumes, partitions and disks.  You can also import disks from another machine.

 

Disk and Volume Status Descriptions

In Disk Management you will usually see you disk as Online and the status as Healthy.  If there are problems you will see them listed here.  Below is a list of statuses you would find on a volume from the book.

  • Failed - Indicates that a volume could not be started automatically, or that the disk is damaged.  If this status message appears, ensure that the disk is properly connected to the system

  • Failed Redundancy - Indicates that the fault tolerance provided by a RAID-5 or mirrored volume is unavailable because one of the disks in the fault tolerant volume is not online.  Different sub-status message may appear in parentheses next to the message indicating that the volume at risk is the system or boot volume, holds the paging file, and so forth.

  • Formatting - A temporary status message that indicated a format operation is currently being carried out on a volume.

  • Healthy - Indicates that a volume is functioning as it should, and no additional actions are required.  If this message is followed by a sub-status message in parentheses indicating that the volume is at risk, I/O errors may have been detected, and Check Disk should be run.

  • Regenerating - Indicated that a missing disk in a RAID-5 volume has been reactivated and is regenerating its data.  Once complete, the status of the volume should return to healthy.

  • Resyncing - Indicated that a mirrored volume is synchronizing information as part of maintaining identical data on both disks.  This message may also appear when mirrored disks are imported, or when an offline disk in a mirrored volume is brought back online.  Once complete, the status of the volume should return to Healthy.

  • Unknown - Indicates that the boot sector of the volume is corrupted, and data on that volume is not accessible.

Below is a list of statuses you would find on a disk, as listed in the book.

  • Audio CD - Indicates that an audio CD is located in a CD or DVD drive.

  • Foreign - Indicates that the disk is a dynamic disk imported from another computer.  To access data on this disk, right-click and select Import Foreign Disks option.

  • Initializing - A temporary status that indicates a basic disk is being converted to a dynamic disk.

  • Missing - Indicates that the disk has been removed, is not properly connected

  • No Media - Indicates that the CD, DVD, or other removable media is empty.

  • Not Initialized - Indicates that a new disk has been added to the system without a valid disk signature.  To make a disk accessible, right-click on the disk and choose the Initialize Disk option.

  • Online - Indicates that the disk is functioning normally, and no additional actions are required.

  • Online (Errors) - Indicates that I/O errors have been detected on a dynamic disk.  Use the Check Disk utility to scan the disk for errors.

  • Offline - Indicates that a disk is no longer accessible.  Attempt to fix this problem by right-clicking on the disk and choosing Reactive Disk.  If that doesn't solve the problem, the issue may relate to the connection or a problem with the drive controller.

  • Unreadable - Typically indicates I/O errors or corruptions on certain portions of the disk.  Use the Rescan Disks command to try and bring the disk back online, or try to repair the problem with the Check Disk utility.

Importing Foreign Disks

If you have problems with a server you can move the hard drive to another server and import it.  If the drive is part of a spanned, striped, or RAID-5 volume, then you must import each drive to access the data.  It will attempt to take the drive letter it had, if it can't it will take the next free drive letter.


Other Disk Maintenance and Management Utilities

Disk Management allows you to do a lot, but sometimes you will have to perform a maintenance task that isn't available in it.

 

Check Disk

Scans your disks for bad sectors and file system errors.  This is similar to the Scandisk tool from earlier versions of Windows/DOS.  You can run the tool using the Check Now button on the Tools tab of the drives properties page.  You can also use the CHKDSK command.

 

Convert

Convert is used to convert your file system from FAT or FAT32 to NTFS.  There is no undoing this conversion.

 

Disk Cleanup

This utility will remove files that probably aren't needed any more.  These files include:

  • Temporary Internet files.

  • Downloaded program files.

  • Files in the Recycle Bin.

  • Windows temporary files.

  • Windows components no longer used.

  • Installed programs no longer used.

Disk Defragmenter

When you save a file to your hard drive it will place it in the first free spot it finds.  This means if you have a large file then your data may be spread out all over the disk.  This data is fragmented, in order for the system to retrieve your data it needs to move the hard drive head to many positions and wait for the data to spin under it.  A disk defragmenter will take the fragments of the file and place them all in the same area so the drive doesn't have to work to hard to retrieve the data.

 

LAB ACTIVITY - Do the lab on page 251. (10 Minutes)

 

Command Line Utilities

Windows Server 2003 comes with some command line utilities that you can use to maintain your system.

  • DISKPART - A tool that allows you to manage disks, volumes and partitions.  This is similar to DOS's FDISK but with more options.

  • FORMAT - This is used to format a new or existing disk.  It will remove all data from the partition or volume.

  • FSUTIL - Allows you to configure advanced settings on the file system, for example disk quota's.

  • MOUNTVOL - Allows you to mount volumes, it requires the globally unique identifer (GUID) of the partitions or volumes.


More Information

 

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