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From: Richard R. <fl...@us...> - 2002-06-23 16:38:29
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Changes by: flatcap
Update of /cvsroot/linux-ntfs/dynamic-disk/linux/Documentation
In directory usw-pr-cvs1:/tmp/cvs-serv8357/linux/Documentation
Added Files:
Config.help Config.in ldm.txt
Log Message:
patches for current kernels
updates to configuration & docs
--- NEW FILE ---
CONFIG_LDM_PARTITION
Say Y here if you would like to use hard disks under Linux which
were partitioned using Windows 2000's or XP's Logical Disk Manager.
They are also known as "Dynamic Disks".
Windows 2000 introduced the concept of Dynamic Disks to get around
the limitations of the PC's partitioning scheme. The Logical Disk
Manager allows the user to repartition a disk and create spanned,
mirrored, striped or RAID volumes, all without the need for
rebooting.
Normal partitions are now called Basic Disks under Windows 2000 and
XP.
For a fuller description read <file:Documentation/ldm.txt>.
If unsure, say N.
CONFIG_LDM_DEBUG
Say Y here if you would like LDM to log verbosely. This could be
helpful if the driver doesn't work as expected and you'd like to
report a bug.
If unsure, say N.
--- NEW FILE ---
dep_bool ' Windows Logical Disk Manager (Dynamic Disk) support' CONFIG_LDM_PARTITION
if [ "$CONFIG_LDM_PARTITION" = "y" ]; then
bool ' Windows LDM extra logging' CONFIG_LDM_DEBUG
fi
--- NEW FILE ---
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:
hda: 102400 sectors w/32KiB Cache, CHS=50/64/32
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
ld...@fl...
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