The following patch implements multipath pool support. It's very
basic functionality, consisting of creating a pool that contains all
the multipath devices on the host. That will cover the common case of
users who just want to discover all the available multipath devices
and assign them to guests.
It doesn't currently allow configuration of multipathing, so for now
setting the multipath configuration will have to continue to be done
as part of the host system build.
Example XML to create the pool is:
<pool type="mpath">
<name>mpath</name>
<target>
<path>/dev/mapper</path>
</target>
</pool>
The target element is ignored, as it is by the disk pool, but the
config code rejects the XML if it does not exist. That behavior
should obviously be cleaned up, but I think that should be done in a
separate patch, as it's really a bug in the config code, not related
to the addition of the new pool type.
Dave