Linux runs in both a hosted and nonhosted partitioned environment.
A hosted partition uses I/O resources that belong to a hosting i5/OS® partition. The hosting i5/OS partition can either be a primary or a secondary partition. The I/O resources that a hosted partition can use from a server include disk, CD, and tape devices.
The hosted logical partition must be started from the hosting i5/OS partition
by varying on a network server description (NWSD). The NWSD is used to control
the logical partition. The logical partition can only be active when the server
is both active and out of restricted state. When i5/OS is in restricted state, all NWSDs
are automatically varied off. An i5/OS partition can host multiple logical
partitions. You need to perform proper capacity planning 
to ensure that the server can support logical partitions.
You should not power on a hosted logical partition using the Work with Partitions Status display. If you power on the logical partition running Linux using the Work with Partitions Status display, none of the virtual I/O devices will be available.
A nonhosted logical partition is not dependent on a hosting i5/OS partition for any I/O resources. The logical partition has its own disk units or the partition makes use of networking support to do a network start. A nonhosted logical partition can be started even if the primary partition is not fully active. A nonhosted logical partition can be started from the Work with Partitions Status display.