Load source placement rules for IBM i logical partitions

You must properly place a disk unit within a system unit or expansion unit before you use the disk unit as the load source for an IBM® i logical partition. The placement rules depend upon the server unit or expansion unit in which the load source is located, and sometimes on the I/O adapter (IOA) that controls the load source.

Read the following rules about load source placement for IBM i logical partitions:

• There is no specific slot requirement for serial-attached SCSI (SAS) disk units. Any slot can contain the load source.
• The load-source IOA must be specified when you create your logical partition.
• Disk compression must be disabled for the load source disk.
• Disk units must have at least 17 GB of usable capacity.
• Disk mirroring requires two load source disk devices in valid load-source positions.
• Any disk IOA that can attach to a system capable of having logical partitions can be used for additional storage capacity after the special requirements for the load-source disk are met.
• Each logical partition has its own single-level storage and hence its own ASP configuration. The ASP configuration rules that apply to systems without logical partitions also apply to logical partitions.
• Disk protection can be defined for a logical partition in the same way as for a nonpartitioned system: parity protection (RAID), mirroring, or mixed. Bus-level mirroring requires two buses in the logical partition.
• Disk units that are already in use by a logical partition cannot be easily added to a different logical partition. You must first remove them from the configuration of the logical partition that is using the disk units before you add them to a different logical partition. In doing so, the system automatically moves any user or system data to other disk units in the same ASP.