REAL WORLD GPT is becoming the primary disk type for Windows Server. With Windows Server 2012 R2, a typical new disk has the GPT partition style with a recovery partition and an EFI system partition.
NOTE You can mark a partition as active by using Disk Management. In Disk Management, press and hold or right-click the primary partition you want to mark as active, and then tap or click Mark Partition As Active. 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
You can use dynamic disks with any current version of Windows and many other operating systems, including most UNIX variants. However, keep in mind that you need to create a separate volume for any operating system not based on Windows.
You can’t use dynamic disks on portable computers. When you are working with non-portable computers and servers, you only can use dynamic disks with drives connected to internal controllers (as well as some eSATA controllers). Although you can’t use dynamic disks with portable or removable drives on these computers, you can connect such a drive to an internal controller or a recognized eSATA controller, and then use Disk Management to import the drive.
Windows Server 2012 R2 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.
Before you convert a basic disk to a dynamic disk, you should make sure that you don’t need to boot the computer to an operating system that doesn’t support 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, the following holds true:
■ There must be at least 1 MB of free space at the end of the disk. Disk Management reserves this free space automatically, but other disk management tools might not.
■ You can’t use dynamic disks on portable computers or with removable media. You can configure these drives only as basic drives with primary partitions.
■ You shouldn’t convert a disk if it contains multiple installations of the Windows operating system. If you do, you might be able to start the computer only by using the installation which did the conversion.
To convert a basic disk to a dynamic disk, follow these steps:
1. In Disk Management, press and hold or 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 tap or click Convert To Dynamic Disk.
2. In the Convert To Dynamic Disk dialog box, select the check boxes for the disks you want to convert. Tap or click OK to continue. This displays the Disks To Convert dialog box, which shows the disks you’re converting.
The buttons and columns in 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.
3. To begin the conversion, tap or click Convert. Disk Management warns you that after the conversion is complete, you won’t be able to start previous versions of Windows from volumes on the selected disks. Tap or click Yes to continue.
4. Disk Management restarts the computer if a selected drive contains the boot partition, system partition, or a partition in use.
Before you can change a dynamic disk back to a basic disk, you must delete all dynamic volumes on the disk. After you do this, press and hold or right-click the disk and select Convert To Basic Disk to change the dynamic disk to a basic disk. You can then create new partitions and logical drives on the disk.
Reactivating dynamic disks
If the status of a dynamic disk is Online (Errors) or Offline, you can often reactivate the disk to correct the problem. You reactivate a disk by following these steps:
1. In Disk Management, press and hold or right-click the dynamic disk you want to reactivate, and then tap or click Reactivate Disk. Confirm the action when prompted.
2. 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. Rescanning can sometimes resolve a problem with drives that show a status of Unreadable. You rescan disks on a computer by choosing Rescan Disks from the Action menu in Disk Management.
Moving a dynamic disk to a new system
An important advantage of dynamic disks over basic disks is that you can easily move dynamic disks from one computer to another. For example, if after setting up a computer you decide that you don’t really need an additional hard drive, you can move it to another computer where it can be better used.
Windows Server 2012 R2 greatly simplifies the task of moving disks to a new system. Before moving disks, you should follow these steps:
1. Open Disk Management on the system where the dynamic disks are currently installed. Check the status of the disks, and ensure that they’re marked as Healthy. If the status isn’t Healthy, you should repair partitions and volumes before you move the disks.
NOTE Drives with BitLocker Drive Encryption cannot be moved by using this technique. BitLocker Drive Encryption wraps drives in a protected seal so that any offline tampering is detected and results in the disk being unavailable until an administrator unlocks it.
2. Check the hard drive subsystems on the original computer and the computer to which you want to transfer the disk. Both computers should have identical hard drive subsystems. If they don’t, the Plug and Play ID on the system drive from the original computer won’t match what the destination computer is expecting. As a result, the destination computer won’t be able to load the right drivers, and the boot attempt might fail.