The Live Partition Mobility (LPM) helps on environment management. BUT, when it doesn't works is a problem.
Recently I received the error HSCLA27C on validate and to fix it I recommend check out your Storage Area Network (SAN) zoning and disk allocation/mask. It is the most common problem IMHO.
About the requirements about zoning and mask:
When you create a LPAR it has two WWNs for virtual fiber channel interface. The first one is active WWN and the second one is inactive WWN.
You or your Storage/SAN team need to create the zoning and allocations exactly for the both WWNs (active and inactive). It is necessary because the the LPM checks all the targets across the disk.
With the correctly zoning and disk allocation for the WWNs active and inactive the LPM will work fine.
More about check out http://www-01.ibm.com/support/docview.wss?uid=isg3T1018971