Using the Disk Storage Types

The term storage type refers to the method that Windows Server 2008 uses to structure disks and their contents. Windows Server 2008 offers three storage types: basic disk, dynamic disk, and removable disk. The storage type you use doesn't depend on the processor architecture-it does depend, however, on whether you are working with fixed or non-fixed disks. When you are working with fixed disks, you can use basic, dynamic, or both storage types on any edition of Windows Server 2008. When you are working with non-fixed disks, the disk has the removable storage type automatically.

Working with Basic and Dynamic Disks

Basic disks use the same disk structure as earlier versions of the Windows operating system. When using basic disks, you are limited to creating four primary partitions per disk, or three primary partitions and one extended partition. Within an extended partition, you can create one or more logical drives. For ease of reference, primary partitions and logical drives on basic disks are known as basic volumes. Dynamic disks were introduced in Windows 2000 as a way to improve disk support by requiring fewer restarts after disk configuration changes, improved support for combining disks, and enhanced fault tolerance using RAID configurations. All volumes on dynamic disks are known as dynamic volumes.

Windows Server 2008 systems can use both basic and dynamic disks. You cannot, however, mix disk types when working with volume sets. All disks, regardless of whether they are basic or dynamic, have fi ve special types of drive sections:

• Active: The active partition or volume is the drive section for system cache and startup. Some devices with removable storage might be listed as having an active partition (though they don't actually have the active partition).
• 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.
• Crash dump: The partition to which the computer attempts to write dump files in the event of a system crash. By default, dump files are written to the %System- Root% folder, but can be located on any desired partition or volume.
• Page file: A partition containing a paging file used by the operating system. Because a computer can page memory to multiple disks, according to the way virtual memory is configured, a computer can have multiple page file partitions or volumes.
• System: The system partition or volume contains the hardware-specific files needed to load the operating system. The system partition or volume can't be part of a striped or spanned volume.

The volume types are set when you install the operating system. On an x86-based computer, you can mark a partition as active to ensure that it is the one from which the computer starts. You can do this only for partitions on basic disks. 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. After the update is complete, the partition becomes a simple volume that's active.

When you install Windows Server 2008 on a new system with unpartitioned disks, disks are initialized as basic disks. When you upgrade to Windows Server 2008, disks with partitions are initialized as basic disks. Windows 2000 had limited support for the faulttolerant features found in Windows NT 4.0. In Windows 2000, you can use basic disks to maintain existing spanning, mirroring, and striping configurations and to delete these configurations. You cannot, however, create new combined or fault-tolerant drive sets using the basic disk type.

In Windows Server 2008, fault-tolerant sets that you created in Windows NT are not supported. Before upgrading to Windows Server 2008, it is recommended that you remove the fault-tolerant features. Start by backing up the data. If you have a mirror set, break the mirror set and then run Windows Server 2008 Setup. If you have a volume set, stripe set, or stripe set with parity, you must delete the set before you upgrade. As long as you have a working backup, you can upgrade the disks to dynamic after installation, re-create the fault-tolerant set, and then restore the data from backup.

TROUBLESHOOTING: You can't use dynamic disks on portable computers or with removable media. You can only configure disks for portable computers and removable media as basic disks with primary partitions. For computers that support booting multiple operating systems (multibooted), keep in mind that only Windows 2000 or later versions of the Windows operating system can use dynamic disks.