RE: mdraid DDF container support

[<Jared_Dominguez DELL com>]

> > Might anyone with more Anaconda development experience have
> suggestions for where to try collecting this one piece of information?
> 
> Short answer:
> Take a look at the function mdexamine in
> pyanaconda/storage/devicelibs/mdraid.py.
> 
> Longer answer:
> I haven't read the DDF spec, but it sounds like there is no way to
> determine the number of component devices without first
> assembling/activating the array. If this is not the case, file a bug
> against mdadm to fix the output of 'mdadm --examine --export'.
> 
> If it is the case that one can never know the number of members of a DDF
> array without first assembling the array, you'll need to add special
> code to anaconda to accommodate setting up an array without knowing the
> number of member devices. Some of the areas you'll need to work to do
> that are
> 
> pyanaconda/storage/devicetree.py:DeviceTree.addUdevDiskDevice
> pyanaconda/storage/devicetree.py:DeviceTree.handleUdevMDMemberFor
> mat
> pyanaconda/storage/devices.py:MDRaidArrayDevice
> pyanaconda/storage/devicelibs/mdraid.py
> 
> Good luck.
> 
> David

Thank you, David. When I glanced at the DDF spec, it seemed to me that mdadm should be able to pass this information on before assembling. I've been reading through the files in pyanaconda/storage quite a bit, especially devicetree.py and devices.py, and considered doing some special casing in devicelibs/mdraid.py. I wasn't confident on that being the best path. However, I just looked in super-ddf.c in the mdadm source, and both detail_super_ddf() and brief_detail_super() have big "FIXME"s, so I think I'll need to patch that up first.

--Jared