Problems using multipath _ md _ lvm with IBM Series I and DS8000

[Hartung, Christopher]

Hi @all,

We've problem installing redhat 5.1 on IBM Power System i 570 native.
Our configuration will look like this:

DS8000_1	=> LUNA	=>	mpath (device-mapper)	=>	PrepBoot
(8 MB), /boot (100 MB), / (rest)
DS8000_2	=> LUNB	=>	mpath (device-mapper)	=>	PrepBoot
(8 MB), /boot (100 MB), / (rest)

Mirroring:
		=> /boot	=> MD0
		=> /		=> MD1		=> lvm

so we've this layers: mpath - md - lvm

the installation of redhat works fine. But after starting the
initprocess of our new system and initialization of the multipath
devices the system can't found any md devices and in effect of this the
system can't find the lvm configuration and gets a kernel panic because
the root filesystem isn't found. 

We found many entrys in mailinglists to configure an new initramdisk but
not really explained in detail. The questions are, would a new init
solve our problem (if so, what must we do?) and would this configuration
above work in this constellation?

Thanks for your answer in advance

So long,

christopher