| Technical |
The LDM manages the whole disk so an ordinary MSDOS style partition is not needed. However, to prevent legacy applications thinking that the disk is unused, Windows creates a dummy partition that fills the disk.
One of the most important legacy applications
is the boot loader. It
doesn't understand the LDM database, but it must still be able to boot the
operating system.
If a disk is converted to a dynamic disk before any creating any partitions
then Windows will create a single partition to fill the disk. Microsoft
have chosen the id 0x42 which was used by the encrypted Secure FileSystem
(SFS)
.
| Device | Start | End | Blocks | Id | System |
|---|---|---|---|---|---|
| /dev/hda1 | 1 | 1037 | 2090560 | 42 | SFS |
If a disk with partitions is converted to a dynamic disk, then the structure will be preserved. Converted disks will be limited to this structure. A case where these partitions is needed is the boot loader. It only understands MSDOS partitions.
| Device | Start | End | Blocks | Id | System |
|---|---|---|---|---|---|
| /dev/hda1 | 1 | 100 | 199773 | 42 | SFS |
| /dev/hda2 | 101 | 700 | 1208731 | 42 | SFS |
| /dev/hda3 | 701 | 1037 | 676001 | 42 | SFS |
The most obvious sign of dynamic disks is a partition of type 0x42. Immediately after the partition table is the Private Header (PRIVHEAD). It gives the location and size of the database. If a dynamic disk is reverted to a basic disk, then the PRIVHEADs will be removed (some of the database will remain).