[RFC, RFT] LDM support (aka Windows Dynamic Volumes)

[Adrian Chadd]

This is awesome!

Is it just read-only, or does it allow creation/destruction of LDM volumes?


Adrian

2012/3/11 Andrey V. Elsukov <bu7cher at yandex.ru>:
> Hi, All
>
> i wrote GEOM_PART_LDM class. It provides basic support of Logical Disk Manager
> partitioning scheme [1]. Since LDM metadata is not documented i used several
> articles found in the web and linux implementation as reference [2].
> Only generic volumes is supported. Spanned, striped and raid5
> configurations aren't implemented. Mirrored volumes also are not shown by default,
> but they can be accessed when kern.geom.part.ldm.show_mirrors=1 (by your own risk).
>
> Currently only LDM on top of MBR is supported. Also only "gpart destroy" is allowed
> with LDM scheme.
>
> you can compile class without patching, the source code is here:
> http://people.freebsd.org/~ae/LDM/
>
> [1] http://en.wikipedia.org/wiki/Logical_Disk_Manager
> [2] http://fxr.watson.org/fxr/source/fs/partitions/?v=linux-2.6
>
> Example:
> /* da1 and da2 disks without geom_part_ldm module */
> # gpart show da1 da2
> =>       63  104857537  da1  MBR  (50G)
>         63       1985    1  ms-ldm-data  (992k)
>       2048     204800    2  ms-ldm-data  [active]  (100M)
>     206848  104648704    3  ms-ldm-data  (49G)
>  104855552       2048       - free -  (1.0M)
>
> =>     32  2097120  da2  MBR  (1.0G)
>       32       31       - free -  (15k)
>       63  2095041    1  ms-ldm-data  (1G)
>  2095104     2048       - free -  (1.0M)
>
> # kldload ./geom_part_ldm.ko
> # gpart show da1 da2
> =>       63  104855489  da1  LDM  (50G)
>         63       1985       - free -  (992k)
>       2048     204800    1  ntfs  (100M)
>     206848  104648704    2  ntfs  (49G)
>
> =>     63  2095041  da2  LDM  (1.0G)
>       63       65       - free -  (32k)
>      128  1024000    1  ntfs  (500M)
>  1024128  1067008    2  ntfs  (521M)
>  2091136     3968       - free -  (2M)
>
> --
> WBR, Andrey V. Elsukov
>