What's the Dynamic disk?
The Dynamic Disk is a physical disk that manages its volumes by using LDM database. What is the LDM database? LDM is an acronym of Logical Disk Manager, and it is a hidden database which size is 1MB at the end of the Dynamic Disk. The 1MB space records all the information of the volumes on a single disk, and also holds some related information on each dynamic disk. Such as Drive Letter, Volume Label, the begin sector of Volume, Volume size, the file system of Volume, and the current dynamic disk is which one and so on.
Each dynamic disk will hold a these information mentioned if there are several dynamic disk on your computer. This means that all dynamic disks are interrelated. The relevance of each dynamic disk let you will see a "Missing" disk which is shown in Windows Disk Management if you remove a dynamic disk from your system. All this is saved in LDM database, so LDM database is vary important the same as Partition Table of Basic Disk. You can know clearly as follows:
The blue area at the beginning of Dynamic Disk is the MBR which saves the information of the Partition Table on the disk. This partition table is not the same as one of Basic Disk. Its main function is to make Windows and Other Disk Manager can know the disk is a dynamic disk instead of an empty disk. The blue at the end of the above is the LDM database.
What's the difference between Basic and Dynamic Disks in Windows?
Microsoft Windows offer two types of disk storage: basic and dynamic.
Basic Disk Storage
Basic storage uses normal partition tables supported by MS-DOS, Microsoft Windows 95, Microsoft Windows 98, Microsoft Windows Millennium Edition (Me), Microsoft Windows NT, Microsoft Windows 2000, Windows Server 2003 and Windows XP. A disk that has been initialized for basic storage is called a basic disk. A basic disk contains basic volumes, such as primary partitions, extended partitions, and logical drives. Additionally, basic volumes include multi-disk volumes that are created by using Windows NT 4.0 or earlier editions, such as volume sets, stripe sets, mirror sets, and stripe sets with parity. Windows XP does not support these multidisk basic volumes. Any volume sets, stripe sets, mirror sets, or stripe sets with parity must be backed up and deleted or converted to dynamic disks before you install Windows XP Professional.
Dynamic Disk Storage
Dynamic storage is supported in the Windows XP Professional, Windows 2000 and Windows Server 2003. A disk that has been initialized for dynamic storage is called a dynamic disk. A dynamic disk contains dynamic volumes, such as simple volumes, spanned volumes, striped volumes, mirrored volumes, and RAID-5 volumes. With dynamic storage, you can perform disk and volume management without restarting the Windows.
Note: Dynamic disks are not supported on portable computers or on Windows XP Home Edition-based computers.
You cannot create mirrored volumes or RAID-5 volumes on the Windows XP Home Edition, Windows XP Professional, or Windows XP 64-Bit Edition-based computers. However, you can use a Windows XP Professional-based computer to create a mirrored or RAID-5 volume on remote computers that are running Windows 2000 Server, Windows 2000 Advanced Server, or Windows 2000 Datacenter Server, or the Standard, Enterprise and the Data Center versions of Windows Server 2003 or the Starter, Basic, Home Premium, Business, Enterprise and Ultimate of Windows Vista.
A disk system can contain any combination of storage types. However, all volumes on the same disk must use the same storage type.
Dynamic Storage Terms
A volume is a storage unit made from free space on one or more disks. It can be formatted with a file system and assigned a drive letter. Volumes on dynamic disks have the following types: simple, spanned, mirrored, striped, or RAID-5.
A simple volume uses free space from a single disk. It can be a single region on a disk or consist of multiple, concatenated regions. A simple volume can be extended within the same disk or onto additional disks. If a simple volume is extended across multiple disks, it becomes a spanned volume.
A spanned volume is created from free disk space that is linked together from multiple disks. You can extend a spanned volume onto a maximum of 32 disks. A spanned volume cannot be mirrored and is not fault-tolerant.
A striped volume is a volume whose data is interleaved across two or more physical disks. The data on this type of volume is allocated alternately and evenly to each of the physical disks. A striped volume cannot be mirrored or extended and is not fault-tolerant. Striping is also known as RAID-0.
A mirrored volume is a fault-tolerant volume whose data is duplicated on two physical disks. All of the data on one volume is copied to other disks for storage. If one of the disks fails, the data can still be accessed from the remaining disk. A mirrored volume cannot be extended. Mirroring is also known as RAID-1.
A RAID-5 volume is a fault-tolerant volume whose data is striped across an array of three or more disks. Parity (a calculated value that can be used to reconstruct data after a failure) is also striped across the disk array. If a physical disk fails, the portion of the RAID-5 volume that was on that failed disk can be re-created from the remaining data and the parity, refer to How to repair a RAID-5 volume? A RAID-5 volume cannot be mirrored or extended.
The system volume contains the hardware-specific files needed to load the Windows (for example, Ntldr, Boot.ini, and Ntdetect.com). The system volume can be, but does not have to be, the same as the boot volume.
The boot volume contains the Windows operating system files located in the %Systemroot% and %Systemroot%\System32 folders. The boot volume can be, but does not have to be, the same as the system volume.
Windows support for Dynamic Volume or not
The following table describes the support case for each Windows.
|Operating System||Simple, Spanned and Striped Volume||Mirrored Volume||RAID-5 Volume|
|Windows 9x/Me, DOS|
|Windows 2000 Professional|
|Windows 2000 Server|
|Windows 2000 Advanced Server|
|Windows XP Home|
|Windows XP Professional|
|Windows Server 2003 Standard|
|Windows Server 2003 Enterprise|
|Windows Vista Ultimate|
|Windows 2008 Server|
|Windows 2008 Web Server|
|Windows 7 Ultimate|