patch-2.4.20 linux-2.4.20/Documentation/ldm.txt

• Lines: 103
• Date: Thu Nov 28 15:53:08 2002
• Orig file: linux-2.4.19/Documentation/ldm.txt
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/Documentation/ldm.txt linux-2.4.20/Documentation/ldm.txt
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+
+            LDM - Logical Disk Manager (Dynamic Disks)
+            ------------------------------------------
+
+Overview
+--------
+
+Windows 2000 and XP use a new partitioning scheme.  It is a complete
+replacement for the MSDOS style partitions.  It stores its information in a
+1MiB journalled database at the end of the physical disk.  The size of
+partitions is limited only by disk space.  The maximum number of partitions is
+nearly 2000.
+
+Any partitions created under the LDM are called "Dynamic Disks".  There are no
+longer any primary or extended partitions.  Normal MSDOS style partitions are
+now known as Basic Disks.
+
+If you wish to use Spanned, Striped, Mirrored or RAID 5 Volumes, you must use
+Dynamic Disks.  The journalling allows Windows to make changes to these
+partitions and filesystems without the need to reboot.
+
+Once the LDM driver has divided up the disk, you can use the MD driver to
+assemble any multi-partition volumes, e.g.  Stripes, RAID5.
+
+To prevent legacy applications from repartitioning the disk, the LDM creates a
+dummy MSDOS partition containing one disk-sized partition.
+
+
+Example
+-------
+
+Below we have a 50MiB disk, divided into seven partitions.
+N.B.  The missing 1MiB at the end of the disk is where the LDM database is
+      stored.
+
+  Device | Offset Bytes  Sectors  MiB | Size   Bytes  Sectors  MiB
+  -------+----------------------------+---------------------------
+  hda    |            0        0    0 |     52428800   102400   50
+  hda1   |     51380224   100352   49 |      1048576     2048    1
+  hda2   |        16384       32    0 |      6979584    13632    6
+  hda3   |      6995968    13664    6 |     10485760    20480   10
+  hda4   |     17481728    34144   16 |      4194304     8192    4
+  hda5   |     21676032    42336   20 |      5242880    10240    5
+  hda6   |     26918912    52576   25 |     10485760    20480   10
+  hda7   |     37404672    73056   35 |     13959168    27264   13
+
+The LDM Database may not store the partitions in the order that they appear on
+disk, but the driver will sort them.
+
+When Linux boots, you will see something like:
+
+Partition check:
+  hda: [LDM] hda1 hda2 hda3 hda4 hda5 hda6 hda7
+
+
+Compiling LDM Support
+---------------------
+
+To enable LDM, choose the following two options: 
+
+  "Advanced partition selection" CONFIG_PARTITION_ADVANCED
+  "Windows Logical Disk Manager (Dynamic Disk) support" CONFIG_LDM_PARTITION
+
+If you believe the driver isn't working as it should, you can enable the extra
+debugging code.  This will produce a LOT of output.  The option is:
+
+  "Windows LDM extra logging" CONFIG_LDM_DEBUG
+
+N.B. The partition code cannot be compiled as a module.
+
+As with all the partition code, if the driver doesn't see signs of its type of
+partition, it will pass control to another driver, so there is no harm in
+enabling it.
+
+If you have Dynamic Disks but don't enable the driver, then all you will see
+is a dummy MSDOS partition filling the whole disk.  You won't be able to mount
+any of the volumes on the disk.
+
+
+Booting
+-------
+
+If you enable LDM support, then lilo is capable of booting from any of the
+discovered partitions.  However, grub does not understand the LDM partitioning
+and cannot boot from a Dynamic Disk.
+
+
+More Documentation
+------------------
+
+There is an Overview of the LDM online together with complete Technical
+Documentation.  It can also be downloaded in html.
+
+  http://linux-ntfs.sourceforge.net/ldm/index.html
+  http://linux-ntfs.sourceforge.net/downloads.html
+
+If you have any LDM questions that aren't answered on the website, email me.
+
+Cheers,
+    FlatCap - Richard Russon
+    ldm@flatcap.org
+