Working with Basic and Dynamic Disks
from Chapter 10, Microsoft Windows 2000 Administrator's Pocket Consultant by William R. Stanek.
Windows 2000 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 2000 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.
Using Basic and Dynamic Disks
When you upgrade to Windows 2000, disks with partitions are initialized as basic disks. When you install Windows 2000 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 Windows NT 4.0. You can use basic drives to maintain existing driving, mirroring, and striping configurations and to delete these configurations. However, you can't create fault tolerant drives using the basic disk type. You'll need to upgrade 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 2000. If you want to upgrade C to the dynamic disk type, you must also upgrade D. To learn how to upgrade a disk from basic to dynamic, see the section of this chapter entitled "Changing Drive Types."
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. On Compaq Alpha-based computers, the system partition or volume must be formatted for the FAT file system. The system partition or volume can't be part of a striped, spanned, or RAID-5 volume.
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. When the computer uses multiple operating systems, the active drive section must contain the startup files for all operating systems loaded on the computer and it must be a primary partition on a basic disk. If you only use Windows 2000, the active drive section must be a simple volume on a dynamic disk (which can be the same volume as the system volume).
Marking an Active Partition
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 and Windows 2000, these files are BOOT.INI, NTDETECT.COM, NTLDR, and BOOTSECT.DOS. You may also need NTBOOTDD.SYS.
Access Disk Management.
Right-click the primary partition you want to mark as active, and then select Mark Partition Active.
Note: You can't mark volumes as active. When you upgrade a basic disk containing the active partition to a dynamic disk, this partition becomes a simple volume that is 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 2000 features. You can't use dynamic disks with previous versions of Windows, but 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 2000 provides the tools you need to upgrade a basic disk to a dynamic disk and to change a dynamic disk back to a basic disk. When you upgrade 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.
Upgrading a Basic Disk to a Dynamic Disk
Before you upgrade a basic disk to a dynamic disk, you should make sure that you don't need to boot the computer to a previous version of Windows. You should also make sure that the disk has 1 MB of free space at the end of the disk. While Disk Management reserves this free space when creating partitions and volumes, disk management tools on other operating systems might not. As a result, the upgrade will fail. Other considerations you should make before upgrading are as follows:
You can't upgrade drives that use sector sizes larger than 512 bytes. If the drive has large sector sizes, you'll need to reformat before upgrading.
You can't upgrade removable media to dynamic disks. You can only configure removable media drives as basic drives with primary partitions.
You can't upgrade 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 upgrade.
You can upgrade 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 upgrade all drives in the set together.
To upgrade a basic disk to a dynamic disk, complete the following steps:
In Disk Management, right-click a basic disk that you want to upgrade, either in the Disk List view or in the left pane of the Graphical view. Then select Upgrade To Dynamic Disk.
In the Upgrade To Dynamic Disk dialog box, select the check boxes for the disks you want to upgrade. If you're upgrading a spanned, striped, mirrored, or RAID-5 volume, be sure to select all the basic disks in this set. You must upgrade the set together. Click OK when you're ready to continue.
As shown in Figure 10-3, the Disks To Upgrade dialog box shows the disks you're upgrading. 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.
Figure 10-3: In the Disks To Upgrade dialog box, notice the Disk Contents and Will Upgrade columns before continuing.
Will Upgrade Specifies whether the drive will be upgraded. If the drive doesn't meet the criteria, it won't be upgraded, and you may need to take corrective action, as described previously.
Details Shows the volumes on the selected drive.
Upgrade Starts the upgrade operation.
If you're ready to begin the upgrade, click Upgrade. Disk Management warns you that once you upgrade 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 REVERT 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 may 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 all drives on a system updates the drive configuration information on the computer. It can sometimes resolve problems with drives that show a status of Unreadable. Because the drive configuration may change as a result of the rescan, you may 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 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 2000 gave no notification of this change).
During reboot of the system, Windows 2000 stated incorrectly that the NTOSKRNL.EXE file needed to be restored on the Windows 2000 root folder. Using the emergency boot disk created as explained in Chapter 14, you could modify the BOOT.INI file and recover the system. Without the emergency boot disk, you'd need to repair the Windows 2000 installation using the Windows 2000 Setup Boot Disks. Creating the Windows 2000 setup disks is also covered in Chapter 14.
Moving a Dynamic Disk to a New System
Windows 2000 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.
Using Basic Disks and Partitions
When you install a new computer or update an existing computer, you'll often need to partition the drives on the computer. You partition drives using Disk Management. Use partitions when you need to boot the computer to Microsoft Windows 95, Windows 98, or Windows NT as well as Microsoft Windows 2000.
Caution: Before you make any changes to hard disk drives, consider the consequences. Changing partition information for drives may result in data loss, and improper configuring of partitions may even prevent system boot. To prevent some configuration problems, Windows 2000 restricts the operations you can perform on system or boot partitions.
Understanding Drive Partitions
Windows 2000 uses two types of partitions—primary and extended.
Primary partitions Drive sections that you can access directly for file storage. Each physical drive can have up to four primary partitions. You make a primary partition accessible to users by creating a file system on it.
Extended partitions Unlike primary partitions, you can't access these directly. Instead, you can configure extended partitions with one or more logical drives that are used to store files. Being able to divide extended partitions into logical drives allows you to divide a physical drive into more than four sections.
On Windows 2000 a physical drive can have up to four primary partitions and up to one extended partition. This allows you to configure drives in one of two ways: using one to four primary partitions or using one to three primary partitions and one extended partition.
Note: With MS-DOS, a physical drive can have only one primary partition. This partition is the boot partition. If you plan to boot a Windows 2000 system in MS-DOS, you should use only one primary partition and then use an extended partition to create additional logical drives.
Assigning Drive Letters
After you partition a drive, you format the partitions to assign drive letters. This is a high-level formatting that creates the file system structure rather than a low-level formatting that sets up the drive for initial use.
You're probably very familiar with the C drive used by Windows 2000. Well, the C drive is simply the designator for a disk partition. If you partition a disk into multiple sections, each section can have its own drive letter. You use the drive letters to access file systems in various partitions on a physical drive. Unlike MS-DOS, which assigns drive letters automatically starting with the letter C, Windows 2000 lets you specify drive letters. Generally, the drive letters C through Z are available for your use.
Note: The drive letter A is usually assigned to the system's floppy drive. If the system has a second floppy drive, the letter B is assigned to it, so you can only use the letters C through Z. Don't forget that CD-ROMs, Zip drives, and other types of media drives need drive letters as well. The total number of drive letters you can use at one time is 24. If you need additional volumes, you can create them using drive paths.
Assigning Drive Paths
In Windows NT 4.0, you could only have 24 active volumes. To get around this limitation, Windows 2000 allows you to mount disks to drive paths. A drive path is set as a folder location on another drive. For example, you could mount additional drives as E:\data1, E:\data2, and E:\data3.
Drive paths can be used with basic and dynamic disks. The only restriction for drive paths is that you mount them on empty folders that are on NTFS drives.
Color Coding Partitions
To help you differentiate between primary partitions and extended partitions with logical drives, Disk Management color codes the partitions. For example, primary partitions may be color coded with a dark blue band and logical drives in extended partitions may be color coded with a light blue band. The key for the color scheme is shown at the bottom of the Disk Management window. You can change the colors using the View Settings dialog box. From Disk Management's View menu, select the Settings option.
Creating Partitions and Logical Drives
In Disk Management you create partitions and logical drives by completing the following steps:
In the Disk Management Graphical view, right-click an area marked Unallocated and then choose Create Partition. This starts the Create Partition Wizard. Read the welcome dialog box, and then click Next. As shown in Figure 10-4, you can now select a partition type.
Select Primary Partition to create a primary partition. Each physical drive can have up to four primary partitions. A primary partition can fill an entire disk or be sized as appropriate for the workstation or server you're configuring.
Select Extended Partition to create an extended partition. Each physical drive can have one extended partition. This extended partition can contain one or more logical drives, which are simply sections of the partition with their own file system.
Note: If a drive already contains an extended partition, the Extended Partition option won't be available. You'll need to delete the existing extended partition and create a new one, which will result in data loss. Note also that you can only create primary partitions on removable drives.
Figure 10-4: In the Create Partition Wizard select a partition type, and then click Next.
Select Logical Drive if you want to create a logical drive within an extended partition.
Tip Although you can size the logical drive any way you want, you may want to take a moment to consider how you'll use logical drives on the current workstation or server. Generally, you use logical drives to divide a large drive into manageable sections. With this in mind, you may want to divide a 21 GB extended partition into 3 logical drives of 7 GB each.
Next you should see the Specify Partition Size dialog box shown in Figure 10-5. This dialog box specifies the minimum and maximum size for the partition in megabytes and lets you size the partition within these limits. Size the partition using the Amount Of Disk Space To Use field.
Specify whether you want to assign a drive letter or path. These options are used as follows:
Assign A Drive Letter To assign a drive letter, choose this option, and then select an available drive letter in the selection list provided.
Mount This Volume To An Empty Folder That Supports Drive Paths To assign a drive path, choose this option, and then type the path to an existing folder or click Browse to search for or create a folder.
Do Not Assign A Drive Letter Or Drive Path To create the partition without assigning a drive letter or path, choose this option. You can assign a drive letter or path later, if necessary.
Figure 10-5: Size the primary partition within the minimum and maximum size limits and then click Next.
Determine whether the partition should be formatted in the Format Partition dialog box, shown in Figure 10-6. If you elect to format the partition, follow the steps described in the following section, "Formatting Partitions."
Figure 10-6: Format a partition by specifying its file system type and volume label.
Click Next and then click Finish. If you add partitions to a physical drive that contains the Windows 2000 operating system, you may inadvertently change the number of the boot partition. As Figure 10-7 shows, Windows 2000 will display a prompt warning you that the number of the boot partition will change. Click Yes.
Figure 10-7: If you update the physical drive containing the operating system, you may need to update the BOOT.INI file.
Disk Management then creates the partition, assigns a drive letter or path, as appropriate, and formats the partition, as appropriate. If you saw a warning prompt previously, you may see another warning prompt telling you to edit the BOOT.INI file. Edit the BOOT.INI file and update the designator for the boot partition as described in the section in this chapter entitled "Updating the Boot Disk." Then immediately reboot the computer.
Formatting creates a file system in a partition and permanently deletes any existing data. This is a high-level formatting that creates the file system structure rather than a low-level formatting that initializes a drive for use. To format a partition, right-click the partition, and then chose Format. This opens the Format dialog box shown in Figure 10-8. If you compare Figures 10-6 and 10-8, you'll see that the available fields are essentially the same. Because of this, you format a drive using the Create Partition Wizard and the Format dialog box using the same techniques. You use the formatting fields as follows:
Volume Label Specifies a text label for the partition. This label is the partition's volume name.
File System Specifies the file system type as FAT, FAT32, or NTFS. FAT is the file system type supported by MS-DOS and Microsoft Windows 3.1, Windows 95, and Windows 98. NTFS is the native file system type for Windows NT and Windows 2000. The section of Chapter 12 entitled "Windows 2000 File Structures" tells you more about NTFS and the advantages of using it with Windows 2000.
Allocation Unit Size Specifies the cluster size for the file system. This is the basic unit in which disk space is allocated. The default allocation unit size is based on the size of the volume and is set dynamically prior to formatting. To override this feature, you can set the allocation unit size to a specific value. If you use lots of small files, you may want to use a smaller cluster size, such as 512 or 1024 bytes. With these settings, small files use less disk space.
Figure 10-8: Format a partition by specifying its file system type and volume label.
Tip If you create a file system as FAT or FAT32, you can later convert it to NTFS by using the Convert utility. You can't, however, convert NTFS partitions to FAT. Often you'll want your boot partition to be FAT and other partitions to be NTFS. With Intel x86 systems, having your system partitions as FAT is often a good idea. This gives you freedom to boot the system under MS-DOS, if necessary.
With RISC (Reduced Instruction Set Computing)–based systems, you don't have the option of using NTFS. The boot partition must be FAT. For details on creating partitions, see the section of this chapter entitled "Understanding Drive Partitions."
Perform A Quick Format Tells Windows 2000 to format without checking the partition for errors. With large partitions, this option can save you a few minutes. However, it's more prudent to check for errors, which allows Disk Management to mark bad sectors on the disk and lock them out.
Enable File And Folder Compression Turns on compression for the disk. Built-in compression is only available for NTFS. Under NTFS, compression is transparent to users and compressed files can be accessed just like regular files. If you select this option, files and directories on this drive are compressed automatically. For more information on compressing drives, files, and directories, see the section entitled "Compressing Drives and Data."
When you're ready to proceed, click OK. Because formatting a partition destroys any existing data, Disk Management gives you one last chance to abort the procedure. Click OK to start formatting the partition. Disk Management changes the status of the drive to reflect the formatting and the percentage of completion. When formatting is complete, the drive status will change to reflect this.
Updating the Boot Disk
When you add partitions to a physical drive that contains the Windows 2000 operating system, the number of the boot partition may change. If this happens, you'll need to update the system's BOOT.INI file. Normally, this file is located on the C drive.
The BOOT.INI file contains entries that look like this:
[boot loader] timeout=30 default=multi(0)disk(0)rdisk(0)partition(3)\WIN2000 [operating systems] multi(0)disk(0)rdisk(0)partition(3)\WIN2000="Microsoft Windows 2000 Server" /fastdetect multi(0)disk(0)rdisk(0)partition(2)\WINNT="Windows NT Server Version 4.00" multi(0)disk(0)rdisk(0)partition(2)\WINNT="Windows NT Server Version 4.00 [VGA mode]" /basevideo /sos multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Workstation Version 4.00" multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Workstation Version 4.00 [VGA mode]" /basevideo /sos
Entries like this tell Windows NT where to find the operating system:
The designators for this entry are used as follows:
multi(0) Designates the controller for the drive, which in this case is controller 0. If the secondary mirror is on a different controller, enter the number of the controller. Controllers are numbered from 0 to 3.
Note: The format for the BOOT.INI entries is the ARC (Advanced RISC Computer) name format. On SCSI systems that don't use SCSI BIOS (basic input/output system), the first field in the entry is scsi(n), where n is the controller number.
disk(0) Designates the SCSI bus adapter, which in this case is adapter 0. On most systems, this is always 0. The exception is for systems with multiple bus SCSI adapters. These systems use the scsi(n) syntax.
rdisk(0) Designates the ordinal number of the disk on the adapter, which in this case is drive 0. With SCSI drives that use SCSI BIOS, you'll see numbers from 0 to 6. With other SCSI drives, this is always 0. With IDE, you'll see either 0 or 1. In most cases, you'll need to change this field—so be sure to enter the number of the secondary mirror drive.
partition(3) Designates the partition that contains the operating system, which in this case is 3.
If the boot partition for Window 2000 changed from 3 to 4, you would update the BOOT.INI file shown earlier as follows:
[boot loader] timeout=30 default=multi(0)disk(0)rdisk(0)partition(4)\WIN2000 [operating systems] multi(0)disk(0)rdisk(0)partition(4)\WIN2000="Microsoft Windows 2000 Server" /fastdetect multi(0)disk(0)rdisk(0)partition(2)\WINNT="Windows NT Server Version 4.00" multi(0)disk(0)rdisk(0)partition(2)\WINNT="Windows NT Server Version 4.00 [VGA mode]" /basevideo /sos multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Workstation Version 4.00" multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Workstation Version 4.00 [VGA mode]" /basevideo /sos
from Microsoft Windows 2000 Administrator's Pocket Consultant by William R. Stanek. Copyright © 1999 Microsoft Corporation.