HSG80 ACS Solution Software V8.6 for IBM AIM Installation and Configuration Guide

Planning Storage 2–3
Configuration Rules
Review the following requirements and conditions to ensure that the storage configuration
you are planning is adequate:
■ Maximum of 128 LUNs: if Command Console LUN (CCL) is enabled, the result is
127 visible LUNs and one CCL
■ Maximum 1.024 TB LUN capacity
■ Maximum 84 physical drives with 2 optional expansion enclosures per storage system
■ Maximum 84 physical devices
■ Maximum 20 RAID-5 storagesets
■ Maximum 8 partitions per storageset or individual disk
■ Maximum 6 physical devices per RAID 1 (mirrorset)
■ Maximum 14 physical devices per RAID-5 storageset
■ Maximum 24 physical devices per RAID 0 (stripeset)
■ Maximum 24 physical devices per striped mirrorset
Device PTL Addressing Convention
The HSG80 controller has six SCSI device ports, each of which connects to a SCSI bus. In
dual-controller subsystems, these device buses are shared between the two controllers.
(The StorageWorks Command Console GUI calls the device ports “channels.”) The
standard BA370 enclosure provides a maximum of four SCSI target identifications (ID)
for each device port. If more target IDs are needed, expansion enclosures can be added to
the subsystem.
The HSG80 controller identifies devices based on a Port-Target-LUN (PTL) numbering
scheme, shown in Figure 2–1. The physical location of a device in its enclosure
determines its PTL.
■ P—Designates the controller's SCSI device port number (1 through 6).
■ T—Designates the target ID number of the device. Valid target ID numbers for a
single-controller configuration and dual-redundant controller configuration are 0 - 3
and 8 - 15, respectively.
■ L—Designates the logical unit (LUN) of the device. For disk devices the LUN is
always 0.