Bug#684708: mdadm: support external metadata arrays correctly

[Michael Tokarev]

On 20.08.2012 14:05, Dmitrijs Ledkovs wrote:
> On 20/08/12 10:42, Michael Tokarev wrote:
[]
>> There's one more thing missing in there: mdmon should be re-started
>> from real root after switching from rootfs -- the takeover.  I guess
>> it needs to be added to mdadm-raid.
> 
> Why restarted... surely it just can carry-on as it was. Since e.g. /run
> doesn't change pre-/post- real-root.

Because it keeps the mdmon and supported libraries mapped from within
rootfs -- neither of which can be freed after deleted by switch_root.
Ie, this way we keep the initial rootfs (the one which comes from
initramfs) dirty.

--takeover/--offroot (does mdadm running from initramfs sets the latter?)
is the way how it is designed to be used.

/mjt