linux/Documentation/ldm.txt
<<
on v18./spa 18./form 18.a on v18 href="../linux+v3.7.1/Documenta > /ldm.txt">on v18.img src="../.sta c/gfx/right.png" alt=">>">on./spa on.spa class="lxr_search">on v ="+search" method="post" onsubmit="return do_search(this);">on v18.input typ hidden" nam navtarget" ion> ">on v18.input typ text" nam search" id search">on v18.buttopttyp submit">Searchon v18Prefs 18./a>on./spa v18 8./div v18 8.form ac > ="ajax+*" method="post" onsubmit="return false;">on.input typ hidden" nam ajax_lookup" id ajax_lookup" ion> ">o v18 8./form o v18 8.div class="headingbottom">
8 81./a>o8 82./a> LDM - Logical Disk Manager (Dynamic Disks)o8 83./a> ------------------------------------------o8 84./a>o8 85./a>Originally Written by FlatCap - Richard Russopt<ldm@flatcap.org>.o8 86./a>Last Updated by AntoptAltaparmakov on 30 March 2007 for Windows Vista.o8 87./a>o8 88./a>Overviewo8 89./a>--------o8 .10"a>o8 11./a>Windows 2000, XP, and Vista use a new parti > ing scheme. It is a completeo8 12./a>replacement for the MSDOS style parti > s. It stores its informa > in ao8 13./a>1MiB journalled database at the end of the physical disk. The size ofo8 14./a>parti > s is limited only by disk space. The maximum number of parti > s iso8 15./a>nearly 2000.o8 160"a>o8 17./a>Any parti > s created under the LDM are called "Dynamic Disks". There are noo8 18./a>longer any primary or extended parti > s. Normal MSDOS style parti > s areo8 19./a>now known as Basic Disks.o8 210"a>o8 21./a>If you wish to use Spa ned, Striped, Mirrored or RAID 5 Volumes, you must useo8 22./a>Dynamic Disks. The journalling allows Windows to make changes to theseo8 23./a>parti > s and filesystems without the need to reboot.o8 24./a>o8 25./a>Once the LDM driver has divided up the disk, you ca use the MD driver too8 260"a>assemble any multi-parti > volumes, e.g. Stripes, RAID5.o8 27./a>o8 28./a>To prevent legacy applica > s from reparti > ing the disk, the LDM creates ao8 29./a>dummy MSDOS parti > contai ing one disk-sized parti > . This is what iso8 310"a>supported with the Linux LDM driver.o8 31./a>o8 32./a>A newer approach that has been implemented with Vista is to put LDM opttop of ao8 33./a>GPT label disk. This is not supported by the Linux LDM driver yet.o8 34./a>o8 35./a>o8 360"a>Exampleo8 37./a>-------o8 38./a>o8 39./a>Below we have a 50MiB disk, divided into seven parti > s.o8 410"a>N.B. The missing 1MiB at the end of the disk is where the LDM database iso8 41./a> stored.o8 42./a>o8 43./a> Device | Offset Bytes Sectors MiB | Size Bytes Sectors MiBo8 44./a> -------+----------------------------+---------------------------o8 45./a> hda | 0 0 0 | 52428800 102400 50o8 46./a> hda1 | 51380224 1003528 849 | 1048576 2048 1o8 47./a> hda2 | 16384 32 0 | 6979584 13632 6o8 48./a> hda3 | 6995968 13664 6 | 10485760 20480 10o8 49./a> hda4 | 17481728 34144 16 | 4194304 8192 4o8 50./a> hda5 | 21676032 42336 20 | 5242880 10240 5o8 51./a> hda6 | 26918912 52576 25 | 10485760 20480 10o8 52./a> hda7 | 37404672 73056 35 | 13959168 27264 13o8 53./a>o8 54./a>The LDM Database may not store the parti > s in the order that they appear opo8 55./a>disk, but the driver will sort them.o8 560"a>o8 57./a>When Linux boots, you will see something like:o8 58./a>o8 59./a> hda: 102400 sectors w/32KiB Cache, CHS=50/64/32o8 60./a> hda: [LDM] hda1 hda2 hda3 hda4 hda5 hda6 hda7o8 61./a>o8 62./a>o8 63./a>Compiling LDM Supporto8 64./a>---------------------o8 65./a>o8 66./a>To enable LDM, choose the following two > s: o8 67./a>o8 68./a> "Advanced parti > select > " CONFIG_PARTITION_ADVANCEDo8 69./a> "Windows Logical Disk Manager (Dynamic Disk) support" CONFIG_LDM_PARTITIONo8 710"a>o8 71./a>If you believe the driver isn't working as it should, you ca enable the extrao8 72./a>debugging code. This will produce a LOT of output. The 128 73./a>o8 74./a> "Windows LDM extra logging" CONFIG_LDM_DEBUGo8 75./a>o8 760"a>N.B. The parti > code ca not be compiled as a module.o8 77./a>o8 78./a>As with all the parti > code, if the driver doesn't see sig s of its typ ofo8 79./a>parti > , it will pass control to another driver, so there is no harm ino8 810"a>enabling it.o8 81./a>o8 82./a>If you have Dynamic Disks but don't enable the driver, then all you will seeo8 83./a>is a dummy MSDOS parti > filling the whole disk. You won't be able to mounto8 84./a>any of the volumes optthe disk.o8 85./a>o8 860"a>o8 87./a>Bootingo8 88./a>-------o8 890"a>o8 90./a>If you enable LDM support, then lilo is capable of booting from any of theo8 91./a>discovered parti > s. However, grub does not understand the LDM parti > ingo8 92./a>and ca not boot from a Dynamic Disk.o8 93./a>o8 94./a>o8 95./a>More Documenta > o8 96./a>------------------o8 97./a>o8 98./a>There is a Overview of the LDM together with complete Technical Documenta > .o8 990"a>It is available for download.o81000"a>o8101./a> http://www.linux-ntfs.org/0"a>o8102./a>o8103./a>If you have any LDM ques > s that aren't answered in the documenta > , emailo8104./a>me.o8105./a>o8106./a>Cheers,o8107./a> FlatCap - Richard Russopo8108./a> ldm@flatcap.orgo81090"a>o81.10"a>
The 1riginal LXR software by the LXR community0"a>, this experimental vers > by lxr@linux.no0"a>. ./div .div class="subfooter"> lxr.linux.no kindly hosted by Redpill Linpro AS0"a>, provider of Linux consulting and opera > s services since 1995. ./div ./body ./html