Working with Basic and Dynamic Disks | Microsoft Windows Server 2003 Administrator[ap]s Pocket Consultant

Windows Server 2003 supports two types of disk configurations:

Basic

The standard disk type used in previous versions of Windows. Basic disks are divided into partitions and can be used with previous versions of Windows.
Dynamic

An enhanced disk type for Windows Server 2003 that can be updated without having to restart the system (in most cases). Dynamic disks are divided into volumes and can only be used with Windows 2000 and Windows Server 2003.

Note

You can't use dynamic disks on portable computers or with removable media.

Using Basic and Dynamic Disks

When you convert to Windows Server 2003, disks with partitions are initialized as basic disks. When you install Windows Server 2003 on a new system with unpartitioned drives, you have the option of initializing the drives as either basic or dynamic.

Basic drives support all the fault-tolerant features found in Microsoft Windows NT 4.0. You can use basic drives to maintain existing spanning, mirroring, and striping configurations and to delete these configurations. However, you can't create new fault-tolerant drive sets using the basic disk type. You'll need to convert to dynamic disks and then create volumes that use mirroring or striping. The fault-tolerant features and the ability to modify disks without having to restart the computer are the key capabilities that distinguish basic and dynamic disks. Other features available on a disk depend on the disk formatting.

You can use both basic and dynamic disks on the same computer. The catch is that volume sets must use the same disk type. For example, if you have mirrored drives C and D that were created under Windows NT 4.0, you can use these drives under Windows Server 2003. If you want to convert C to the dynamic disk type, you must also convert D. To learn how to convert a disk from basic to dynamic, see the section of this chapter entitled "Changing Drive Types."

Disk configuration tasks that you can perform with basic and dynamic disks are different. With basic disks, you can:

Format partitions and mark them as active
Create and delete primary and extended partitions
Create and delete logical drives within extended partitions
Convert from a basic disk to a dynamic disk

With dynamic disks, you can:

Create and delete simple, striped, spanned , mirrored, and RAID-5 volumes
Remove a mirror from a mirrored volume
Extend simple or spanned volumes
Split a volume into two volumes
Repair mirrored or RAID-5 volumes
Reactivate a missing or offline disk
Revert to a basic disk from a dynamic disk (requires deleting volumes and reload)

With either disk type, you can:

View properties of disks, partitions, and volumes
Make drive letter assignments
Configure security and drive sharing

Special Considerations for Basic and Dynamic Disks

Whether you're working with basic or dynamic disks, you need to keep in mind three special types of drive sections:

System

The system partition or volume contains the hardware-specific files needed to load the operating system.
Boot

The boot partition or volume contains the operating system and its support files. The system and boot partition or volume can be the same.
Active

The active partition or volume is the drive section from which the computer starts.

Note

On multiboot systems with pre “Windows 2000 operating systems, the active drive section might need to contain the startup files for all operating systems loaded on the computer and might also need to be a primary partition on a basic disk. You can't mark an existing dynamic volume as the active volume, but you can convert a basic disk containing the active partition to a dynamic disk. Once the update is complete, the partition becomes a simple volume that's active.

Marking an Active Partition

Windows Server 2003 supports two key CPU architectures: x86 and Itanium. On an x86-based computer, you can mark a partition as active by completing the following steps:

Make sure that the necessary startup files are on the primary partition that you want to make the active partition. For Windows NT, Windows 2000 Server, and Windows Server 2003, these files are Boot.ini, Ntdetect.com, Ntldr, and Bootsect.dos. You might also need Ntbootdd.sys.
Access Disk Management.
Right-click the primary partition you want to mark as active, and then select Mark Partition As Active.

Note

You can't mark dynamic disk volumes as active. When you convert a basic disk containing the active partition to a dynamic disk, this partition becomes a simple volume that's active automatically.

Changing Drive Types

Basic disks are designed to be used with previous versions of Windows. Dynamic disks are designed to let you take advantage of the latest Windows features. Only computers running Windows 2000 or Windows Server 2003 can use dynamic disks. However, you can use dynamic disks with other operating systems, such as UNIX. To do this, you need to create a separate volume for the non-Windows operating system. You can't use dynamic disks on portable computers.

Windows Server 2003 provides the tools you need to convert a basic disk to a dynamic disk and to change a dynamic disk back to a basic disk. When you convert to a dynamic disk, partitions are changed to volumes of the appropriate type automatically. You can't change these volumes back to partitions. Instead, you must delete the volumes on the dynamic disk and then change the disk back to a basic disk. Deleting the volumes destroys all the information on the disk.

Converting a Basic Disk to a Dynamic Disk

Before you convert a basic disk to a dynamic disk, you should make sure that you don't need to boot the computer to other versions of Windows. Only computers running Windows 2000 or Windows Server 2003 can use dynamic disks.

With MBR disks, you should also make sure that the disk has 1 MB of free space at the end of the disk. Although Disk Management reserves this free space when creating partitions and volumes, disk management tools on other operating systems might not. Without the free space at the end of the disk, the conversion will fail.

With GPT disks, you must have contiguous, recognized data partitions. If the GPT disk contains partitions that Windows doesn't recognize, such as those created by another operating system, you can't convert to a dynamic disk.

With either type of disk:

You can't convert drives that use sector sizes larger than 512 bytes. If the drive has large sector sizes, you'll need to reformat before converting.
You can't use dynamic disks on portable computers or with removable media. You can only configure these drives as basic drives with primary partitions.
You can't convert a disk if the system or boot partition is part of spanned, striped, mirrored, or RAID-5 volume. You'll need to stop the spanning, mirroring, or striping before you convert.
You shouldn't convert a disk if it contains multiple installations of the Windows operating system. If you do, you might only be able to start the computer using Windows Server 2003.
You can convert disks with other types of partitions that are part of spanned, striped, mirrored, or RAID-5 volumes. These volumes become dynamic volumes of the same type. However, you must convert all drives in the set together.

To convert a basic disk to a dynamic disk, complete the following steps:

In Disk Management, right-click a basic disk that you want to convert, either in the Disk List view or in the left pane of the Graphical View. Then select Convert To Dynamic Disk.
In the Convert To Dynamic Disk dialog box, select the check boxes for the disks you want to convert. If you're converting a spanned, striped, mirrored, or RAID-5 volume, be sure to select all the basic disks in this set. You must convert the set together. Click OK when you're ready to continue.
The Disks To Convert dialog box shows the disks you're converting. The buttons and columns on this dialog box contain the following information:
- Name Shows the disk number.
- Disk Contents Shows the type and status of partitions, such as boot, active, or in use.
- Will Convert Specifies whether the drive will be converted. If the drive doesn't meet the criteria, it won't be converted, and you might need to take corrective action, as described previously.
- Details Shows the volumes on the selected drive.
- Convert Starts the conversion.
If you're ready to begin the conversion, click Convert. Disk Management warns you that once you finish the conversion you won't be able to boot previous versions of Windows from volumes on the selected disks. Click Yes to continue.
Disk Management will restart the computer if a selected drive contains the boot partition, system partition, or a partition in use.

Changing a Dynamic Disk Back to a Basic Disk

Before you can change a dynamic disk back to a basic disk, you must delete all dynamic volumes on the disk. Once you do this, right-click the disk and select the Convert To Basic Disk command. This changes the dynamic disk to a basic disk and you can then create new partitions and logical drives on the disk.

Reactivating Dynamic Disks

If the status of a dynamic disk displays as Online (Errors) or Offline, you can often reactivate the disk to correct the problem. You reactivate a disk by completing the following steps:

In Disk Management, right-click the dynamic disk you want to reactivate, and then select Reactivate Disk. Confirm the action when prompted.
If the drive status doesn't change, you might need to reboot the computer. If this still doesn't resolve the problem, check for problems with the drive, its controller, and the cables. Also, make sure that the drive has power and is connected properly.

Rescanning Disks

Rescanning all drives on a system updates the drive configuration information on the computer. It can sometimes resolve a problem with drives that show a status of Unreadable. Because the drive configuration might change as a result of the rescan, you might need to update the Boot.ini file for the computer, as discussed later in this chapter in the section entitled "Updating the Boot Disk."

You rescan disks on a computer by selecting Rescan Disk from Disk Management's Action menu.

Real World

Take a screenshot of the disk configuration in Disk Management before scanning and after scanning to double-check the configuration for changes. On my primary server the original configuration had a floppy disk drive on A; logical drives on C, D, E, and F; a removable drive on G; and a CD-ROM drive on H. After rescanning, the removable drive was on B, and, as a result, the number of the boot partition changed (and Windows Server 2003 gave no notification of this change).

During reboot of the system, Windows Server 2003 stated incorrectly that the Ntoskrnl.exe file needed to be restored on the Windows Server 2003 root folder. Using the emergency repair disk created as explained in Chapter 15 , "Data Backup and Recovery," you could modify the Boot.ini file and recover the system. Without the emergency repair disk, you'd need to repair the Windows Server 2003 installation using the Windows Server 2003 CD and the Recovery Console. Installing the Windows Server 2003 Recovery Console is also covered in Chapter 15.

Moving a Dynamic Disk to a New System

Windows Server 2003 makes the task of moving drives to a new system a lot easier. If you want to move a dynamic drive to a new computer, follow these steps:

Access Disk Management on the system where the dynamic drives are currently installed.
Check the status of the drives and ensure that they're marked as healthy. If the status isn't healthy , you should repair partitions and volumes, as necessary, before you move the disk drives.
Remove drive letters and drive paths that reference the drives, as described in the section of this chapter entitled "Assigning Drive Letters and Paths."
If the drives are hot-swappable and this feature is supported on both systems, remove the drives, and then install them on the destination computer. Otherwise, turn off both computers. Remove the drives from the original system and then install them on the new system. When you're finished, turn the computers back on.
On the destination computer, from the Action menu select Rescan Disks. When the scan finishes, right-click any disk marked Foreign, and then click Import Foreign Disks.