On Fri, 11 Jul 2014 19:09:48 -0600 Chris Murphy [off-list ref]
wrote:

quoted

7. I am sure I read somewhere (can't find the source anymore) that the "new" RAID features of LVM2 are based on a fork from the md code. If this is true, are you guys are contributing to that project as well?

It's a good question, I'm not certain but my understanding is device mapper is leveraging existing md code in the kernel, rather than having forked and duplicated that code. They have their own user space tools and on-disk metadata so you can't use mdadm to manage it.

Your understanding is correct.  It is the same code for managing RAID
functionality, but different code for managing metadata and different
user-space tools.
I'm hoping that one day the RAID support in LVM2 will be better than mdadm,
and then I can just fade away and no-one will notice that I am gone.

http://downatthirdman.files.wordpress.com/2010/06/grinning-chesire-cat.jpg

NeilBrown