 |
| Copyright ©
2000 Mark Russinovich |
Last Updated April 17, 2000
|
| Introduction |
Windows 2000
introduces a new type of disk partitioning scheme that is managed by a
component called the Logical Disk Manager (LDM). Basic disks implement
standard DOS-style partition tables, whereas Dynamic disks use LDM partitioing.
LDM partitioning offers several advantages over DOS partitioing including
replication across disks, on-disk storage of advanced volume configuration
(spanned volume, mirrored volumes, striped volumes and RAID-5 volumes). My
March/April two-part series on Windows NT/2000 storage management in Windows
2000 Magazine describes the details of each partitioing scheme.
Other than the Disk Management
MMC-snapin and a tool called dmdiag in the Windows 2000 Resource Kit,
there are no tools for investigating the internals of the LDM on-disk database
that describes a system's partitioning layout. LDMDump is a utility that
lets you examine exactly what is stored in a disk's copy of the system LDM
database. LDMDump shows you the contents of the LDM database private
header, table-of-contents, and object database (where partition, component and
volume definitions are stored), and then summarizes its finding with partition
table and volume listings.
LDMDump works on Windows
2000. |
| Usage |
To use
LDMDump simply pass it the identifier of a disk.
usage: ldmdump [-?]
[-d#] |
| |
-? |
Displays the
supported options and the units of measurement used for output
values. |
| |
-d# |
Specifies the
number of the disk for LDMDump to examine. For example, "ldmdump
/d0" has LDMDump show the LDM database information stored on disk
0. |
| How it Works |
There
are no published APIs available for obtiaining detailed information about a
disk's LDM partitioing, and the LDM database format is completely undocumented.
LDMDump was developed based on study of LDM database contents on a
variety of different systems and under changing conditions. |
| More Information |
For
more information on the LDM on-disk structure, see:
For information on how Windows NT
4.0 stores advanced volume information, see:
|
Download LDMDump (17KB)
|
 |