Managing and Troubleshooting Desktop Storage

Terms you'll need to understand:

• Basic versus Dynamic disks

• Partitions, volumes, and logical drives

• Simple, spanned, and striped volumes

• The diskpart.exe utility

• NT File System (NTFS) volumes

• The convert.exe utility

• Troubleshooting disk drives

• Troubleshooting removable storage

• Disk defragmentation

Techniques you'll need to master:

• Using the Disk Management console

• Monitoring and troubleshooting disks using the Performance console

• Using the Disk Defragmenter and Disk Cleanup Wizard

• Selecting a file system for Windows XP Professional

• Using convert.exe to convert a File Allocation Table (FAT) volume to NTFS

• Using diskpart.exe to manage disk drives and volumes from the command line

• Creating simple, spanned, and striped volumes

• Converting from Basic to Dynamic disks and back again

• Troubleshooting disk drives, CD-ROM, and Universal Serial Bus (USB)–based storage.

For a desktop support technician, the number of distress calls from wayward users who have lost their files can be daunting. However, the storage options supported in Windows XP combine a lot of the old and a bit of the new in terms of things Windows XP can do.

Disk storage is more than about finding lost files. In this chapter, we cover how to support and troubleshoot hard disks and explore available options under Windows XP for creating partitions, formatting drive volumes, and managing disk administration.

Disk Storage Administration

If you are familiar with managing and troubleshooting hard disks and volumes under Windows 2000, you'll be comfortable working with disk-storage administration in Windows XP. For desktop support technicians who are familiar with Windows NT 4, Windows XP Professional introduces some new concepts, such as Basic and Dynamic disk storage.

Basic Disks

A Windows XP Basic disk, similar to the disk configuration under earlier versions of Windows, is a physical disk with primary and extended partitions. As long as you use the FAT file system, Windows XP Professional and Home editions, Windows 2000, Windows NT, Windows 9x, and MS-DOS operating systems all can access Basic disks.

On a Basic disk, you can create up to three primary partitions and one extended partition, four primary partitions, or one extended partition with logical drives.

Windows XP supports FAT primary partitions up to 4GB in size. Windows 9x/Me and MS-DOS support only 2GB primary partitions.

If you discover you've created a partition that's too small, you cannot extend it using the Disk Management Microsoft Management Console. However, if you use the diskpart.exe command-line utility shown in Figure 3.1, you can extend a Basic disk partition to contiguous unallocated space. The partition must use the NTFS format and cannot be the system or boot partition.

Figure 3.1 The DiskPart utility, which enables you to extend partitions and convert Basic disks to Dynamic disks.

Basic disks store their configuration information in the master boot record (MBR), which is stored on the first sector of the hard drive. The configuration information consists of the disk's partition information.

Basic disks support spanned volumes (volume sets), striped volumes (stripe sets), mirrored volumes (mirror sets), and Redundant Array of Independent Disks (RAID) Level 5 volumes (stripe sets with parity) that were created (and named) under Windows NT 4.

Mirrored and RAID-5 volumes are fault-tolerant volumes designed to withstand single disk failures. They are only available under the Windows 2000 Server or Windows Server 2003 family of server operating systems. Windows XP does not support these types of volumes on either Basic or Dynamic disks.

Dynamic Disks

A Windows XP Dynamic disk is a physical disk that does not use conventional partitions or logical drives. A Dynamic disk is a single partition that can be divided into separate volumes. You can even resize a volume "on the fly" (without a reboot).

Dynamic disks are combined into collective "disk groups," which helps to organize them. All Dynamic disks in a computer are members of the same disk group. Each disk in a disk group stores replicas of the group's configuration data in a region known as the Logical Disk Manager (LDM) metadata partition.

This configuration data is stored in a 1MB region at the end of each Dynamic disk and is the reason you must have at least 1MB of empty disk space for the LDM to convert a disk from Basic to Dynamic.

Dynamic disks can contain an unlimited number of volumes; you are not restricted to four volumes per disk, as you are with Basic disks, and those volumes can be extended if they are formatted with NTFS. To convert a volume from FAT to NTFS, use the convert.exe volume: /FS:NTFS command, where volume is the logical letter of the drive.

Locally, regardless of the type of file system, only computers running Windows XP Professional, Windows 2000, or Windows Server 2003 recognize Dynamic disks. Windows XP Home Edition does not offer Dynamic disks. Dynamic disks are not supported on portable computers.

Managing Basic and Dynamic Disks

Basic and Dynamic disks are Windows XP's way of managing hard disk configuration. If you're migrating to Windows XP from Windows NT 4, the Dynamic disk concept might seem unfamiliar in the beginning, but once you understand the differences, working with Dynamic disks is not complicated. You can format partitions with FAT16, FAT32, or NTFS on a Basic or a Dynamic disk. FAT and NTFS are discussed later in this chapter.

From the Disk Management console, you can only format a dynamic volume as NTFS. You must use Windows XP Explorer to format a dynamic volume as FAT or FAT32. Table 3.1 compares the terms used with Basic and Dynamic disks.

Table 3.1 A Cross-Reference of Terms Used with Basic and Dynamic Disks

You can convert a Basic disk to a Dynamic disk using the DiskPart command-line utility mentioned earlier or the Disk Management MMC shown in Figure 3.2.

Figure 3.2 Converting a Basic disk to a Dynamic disk.

If you are upgrading from Windows 98 or Windows Me to Windows XP Professional, do not make changes to your disk configuration, such as converting to Dynamic disks and volumes, if you ever want to uninstall XP and revert back to the previous operating system.

Dynamic disks have some additional limitations. You can install Windows XP on a dynamic volume that you converted from a Basic disk, but you can't extend either the system or the boot partition. Additionally, any disk troubleshooting tools you've used might not be able to read the dynamic Disk Management database!

Dynamic disks are only supported on desktop or server systems that use Small Computer System Interface (SCSI), Fibre Channel, Serial Storage Architecture (SSA), Integrated Drive Electronics (IDE), Enhanced IDE (EIDE), Ultra Direct Memory Access (DMA), or Advanced Technology Attachment (ATA) interfaces.

Dynamic disks are not supported on portable computers, removable disks (such as Jaz or Zip drives), and disks connected via USB or FireWire (IEEE 1394) interfaces. If you need to configure an IEEE 1394 disk drive to dynamic, see Knowledge Base Article 299598. They are also not supported on Windows XP Home Edition.

They are also not supported on hard drives with a sector size larger than 512 bytes. Cluster disks—groups of several disks that serve to function as a single disk—are not supported either.

Converting Basic Disks to Dynamic Disks

When you perform a new installation of Windows XP Professional or when you perform an upgrade installation from Windows 98, Windows Me, or Windows NT Workstation 4.0, the computer system defaults to Basic disk storage.

If you upgrade from Windows 2000 Professional (or if you import a "foreign disk" from Windows 2000 Server or a later version), you can configure one or more of the disk drives as Dynamic. You can use Windows XP's Disk Management console (an MMC snap-in), shown in Figure 3.2, to convert a Basic disk to a Dynamic disk. To access Disk Management, click Start, All Programs, Administrator Tools, Computer Management. Or simply right-click the My Computer icon from the Start menu and click Manage. You'll find Disk Management by expanding the Disk Management category.

You must be a member of the local Administrators group to make any changes to the computer's disk management configuration. Before you upgrade disks, close any programs that are running on those disks.

As mentioned earlier, for the conversion to succeed, any disks to be converted must contain at least 1MB of unallocated space. Disk Management automatically reserves this space when creating partitions or volumes on a disk, but disks with partitions or volumes created by other operating systems might not have this space available. (This space can exist even if it is not visible in Disk Management.)

Windows XP requires this minimal amount of disk space to store an LDM database, which is maintained by the operating system that created it.

To convert a Basic disk to a Dynamic disk using the Disk Management console, perform the following steps:

1. Open the Disk Management tool.

2. Right-click the Basic disk you want to change to a Dynamic disk and then click Convert to Dynamic Disk.

Because the conversion from Basic to Dynamic is per physical disk, all volumes on a physical disk must be either Basic or Dynamic. When converting from a Basic to a Dynamic disk, you do not need to restart your computer unless you are converting the system or boot partitions or if the partition contained the page file.

To change or convert a Basic disk to a Dynamic disk from the Windows XP command line, perform these steps:

1. Open a command prompt window, type diskpart, and press Enter.

2. Type commands or help to view a list of available commands.

3. Type select disk 0 to select the first hard disk (select disk 1 to select the second hard disk, and so on) and press Enter.

4. Type convert dynamic and press Enter.

5. Type exit to quit the diskpart.exe tool and then restart the computer to have the new configuration take effect (see Figure 3.1).

You can use the DiskPart utility to create mount points for hard drives through empty folders on NTFS drives. In other words, rather than define a volume with a drive letter, you can link it back to an empty folder on an NTFS formatted drive.

You also can use DiskPart to import foreign disks into computers running XP. This technique is explained in the section "Moving Disks to a Different Computer."

In addition to using diskpart.exe, you can manage FAT, FAT32, and NTFS file systems with the fsutil.exe command-line utility.

Fsutil.exe manages disk quotas, reparses (mount) points, and performs several other advanced disk-related tasks. Type fsutil at a command prompt to view a list of supported commands (see Figure 3.3).

Figure 3.3 The Windows XP fsutil.exe command provides file system information, including sector size.

When you convert a Basic disk to a Dynamic disk, any existing partitions on the Basic disk become simple volumes on the Dynamic disk. Any existing striped volumes or spanned volumes become dynamic striped volumes or dynamic spanned volumes.

Reverting Dynamic Disks to Basic Disks

To revert from a Dynamic disk back to a Basic disk, you must remove all volumes from the Dynamic disk first. After you change a Dynamic disk back to a Basic disk, you can create only partitions and logical drives on that disk.

To convert a Dynamic disk to a Basic disk, perform the following steps:

1. Open Disk Management.

2. Right-click the Dynamic disk you want to change back to a Basic disk and then click Convert to Basic Disk.

Moving Disks to a Different Computer

When you relocate a Dynamic disk from one computer to another, you are moving the disk from one disk group to another. Initially, the disk is perceived as "foreign" when it is connected.

When you connect a foreign Dynamic disk, you need to rescan all drives and then import the foreign disk. This procedure updates the disk's metadatabase. Importing a disk merges the disk's information with the LDM database on the host computer.

Along with disk configuration information, the LDM database stores drive letter assignments. Imported drives keep their original drive letters unless the letters are used by the new host system. If a driver letter is already in use, the system assigns the next available drive letter. To eliminate conflicts, you can remove the drive letters from the volumes before moving the disk.

Because volumes can span multiple disks, when you move multidisk volumes, always move all the disks that compose the volume.

Don't move a disk that contains system or boot volumes to another computer unless you need to recover data. You might also encounter problems if you attempt to move the Dynamic disk back to its original computer. However, you can successfully move Basic disks that have system or boot volumes in this manner because they don't contain a dynamic LDM database.

You can use the diskpart.exe command-line tool or Disk Management to import disks.

To relocate disks to another computer, perform the following steps:

1. First, before you disconnect the disks, look in Disk Management and make sure the status of the volumes on the disks is "healthy." If the status is not healthy, repair the volumes before you move the disks.

2. Turn the source computer off, remove the physical disks, and then install the physical disks on the target computer. Restart the target computer.

3. Open Disk Management.

4. Click Action and then click Rescan Disks.

5. The disk that you move is designated Dynamic/Foreign instead of Dynamic. Right-click the disk and click Import Foreign Disks.

6. The Foreign Disk Volumes dialog box appears, indicating the size, condition, and type of the volume on the imported drive.

7. Click OK to add the disks.

Reactivating Missing or Offline Disks

With LDM, every disk knows about every other disk in your system. When a disk can't be located, it does not disappear from Disk Management. It is simply designated "missing," as shown in Figure 3.4.

Figure 3.4 A drive designated as missing.

A Dynamic disk might be labeled missing when it is corrupted, powered down, or disconnected. Only Dynamic disks can be reactivated—not Basic disks.

Disks are labeled missing because other disks in the disk group share LDM information that expects the disk to be connected and functioning.

To reactivate a missing or offline disk, perform the following steps:

1. Open Disk Management.

2. Right-click the Offline disk whose status is missing and then click Reactivate Disk.

3. The disk should be titled Online after the disk is reactivated.