Windows 8 : Managing Disk Drives and File Systems - Using Basic and Dynamic Disks

Basic disks can have both primary and extended partitions. A primary partition can be used to start the operating system. Although you cannot subdivide a primary partition, you divide extended partitions into one or more logical drives and then access the logical drives independently of each other.

Dynamic disks are divided into volumes, with the simple volume being the most common volume type. A simple volume is a volume on a single disk, which can be used to start the operating system. Dynamic volumes, on the other hand, combine space from multiple physical drives.

Whether working with basic or dynamic disks, you should pay particular attention to five special types of drive sections on MBR disks:

Each computer has one active, one system, one boot, and one crash dump partition or volume and these partitions or volumes can be combined. The page file designation is the only drive designation that you might see on multiple partitions or volumes.

Windows 8 makes it much easier to add new physical disks to a computer. After you install the disks following the disk manufacturer’s instructions, you need to log on and start Disk Management. If the new disks have already been initialized, meaning they already have disk signatures allowing them to be read and written to, they should be brought online automatically if you choose Rescan Disks from the Action menu. If you are working with new disks that have not been initialized, meaning they don’t have disk signatures, Disk Management will start the Initialize And Convert Disk Wizard as soon as Disk Management starts and detects the new disks.

You can use the Initialize And Convert Disk Wizard to initialize the disks by completing the following steps:

If you don’t want to use the wizard, you can close it and use Disk Management instead to view and work with the disk. In the Disk List view, the disk is marked with a red icon that has an exclamation point, and the disk’s status is listed as Not Initialized. Press and hold or right-click the disk’s icon, and then tap or click Initialize Disk. Confirm the selection (or add to the selection if more than one disk is available for initializing), and then tap or click OK to start the initialization of the disk.

You can change partition table styles from MBR to GPT or from GPT to MBR. Changing partition table styles is useful when you want to move disks between computers that have different processor architectures or you receive new disks that are formatted for the wrong partition table style. You can convert partition table styles only on empty disks, however. This means the disks must be either new or newly formatted. You could, of course, empty a disk by removing its partitions or volumes.

You can use both Disk Management and DiskPart to change the partition table style. To use Disk Management to change the partition style of an empty disk, start Computer Management from the Administrative Tools in Control Panel or type compmgmt.msc in the Apps Search box and then press Enter. In Computer Management, expand the Storage node, and then select Disk Management. All available disks are displayed. Press and hold or right-click the disk to convert in the left pane of the Graphical view, and then tap or click Convert To GPT Disk or Convert To MBR Disk, as appropriate.

To use DiskPart to change the partition style of an empty disk, invoke DiskPart by typing diskpart at an elevated command prompt, and then select the disk you want to convert. For example, if you want to convert Disk 2, type select disk 2. After you select the disk, you can convert it from MBR to GPT by typing convert gpt. To convert a disk from GPT to MBR, type convert mbr.

You don’t normally need to change a partition’s designation. If you are using only Windows 8 or if you are multibooting to Windows 8 and any other version of Windows, you do not have to change the active partition. With MBR disks, the active partition is typically the primary partition or the first simple volume on Disk 0. If you install Windows 8 on drive C and Windows 2000 or a later version on a different partition, such as drive D, you don’t need to change the active partition to boot Windows 8 or the other operating system. However, if you want to boot a non-Windows operating system, you usually have to mark its operating system partition as active and then reboot to use that operating system.

To mark a partition as active, complete the following steps:

Example 1 shows a sample DiskPart session for setting the active partition. As you can see, when you first start DiskPart, it shows the DiskPart program name and the version you are using, as well as the name of the computer. You then select the disk you want to work with and list its partitions. In this example, you select Disk 0 to work with, list its partitions, and then select Partition 1. Once you’ve selected a disk and a partition on that disk, you can work with that partition. Simply type the Active command at this point and press Enter to set the partition as active. When you have finished, quit DiskPart using the Exit command.

C:>diskpart

Microsoft DiskPart version 6.2.8250
Copyright (C) 1999-2012 Microsoft Corporation.
On computer: ENGPC85

DISKPART> select disk 0

Disk 0 is now the selected disk.

DISKPART> list partition

  Partition ###  Type              Size     Offset
  -------------  ---------------- -------  -------
  Partition 1    Primary           932 GB  1024 KB

DISKPART> select partition 1

Partition 1 is now the selected partition.

DISKPART> active

DiskPart marked the current partition as active.

DISKPART> exit

The easiest way to convert a basic disk to a dynamic disk or vice versa is to use Disk Management. When you upgrade to a dynamic disk, partitions are automatically changed to volumes of the appropriate type. Any primary partitions become simple volumes. Any logical drives in an extended partition become simple volumes. Any unused (free) space in an extended partition is marked as Unallocated. 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.

Before you convert a basic disk to a dynamic disk, you should be sure that you don’t need to boot the computer to a previous version of Windows. You should also be 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; as a result, the conversion will fail. It is also important to note the following restrictions:

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

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