Your company has a Microsoft Hyper-V Server 2008 R2 environment. You manage the environment by using Microsoft System Center Virtual Machine Manager （VMM） 2008 R2. You plan to install 3 host servers and 15 child partitions in the virtual environment. You will perform child partition placements by using SAN migration. You need to place the appropriate number of child partitions on each logical unit number （LUN） to support SAN migrations.
How many child partitions should you place on each LUN？（）