IBM System Storage DS3000, Programming Manual

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When you first turn on the power to a storage subsystem, the Storage Manager software automatically
detects the HBA host ports. Initially, all detected host ports belong to a default group. You can use script
commands to identify the WWIDs on a storage subsystem and, if you choose, change them. If you move
an HBA host port, you must remap any Volume-to-LUN mappings. Access to your data is lost until you
remap the logical drives.
The maximum number of HBA host ports that you can logically define for your storage subsystem
depends on the type of controller in the storage subsystem. The following table lists the maximum
number of HBA host ports that you can define.
Table 4-6. Maximum Number of HBA Host Ports per Controller
Controller Models Maximum Number of Host Ports
DS3200 64
DS3300 64
DS3400 64
DS3500 256
DCS3700 256
DCS3700 storage subsystem
with Performance Module
Controllers 1024
DS3950 640
DS4100 256
DS4300 256
DS4200 256 (before controller firmware
7.xx.xx.xx)
1024 (with controller firmware 7.xx.xx.xx
and higher)
DS4400 512
DS4500 512
DS4700 256 (before controller firmware
7.xx.xx.xx)
640 (with controller firmware 7.xx.xx.xx
and higher)
DS4800 512 (before controller firmware
7.xx.xx.xx)
2048 (with controller firmware 7.xx.xx.xx
and higher)
DS5020 640
DS5100 2048
DS5300 2048
Logical Unit Numbers
In the context of the CLI commands and the script commands, a logical unit number (LUN) is a unique
value that identifies the logical drives in a storage subsystem. The hosts identify the logical drives that
they want to access using the LUN values. When you create a logical drive, the firmware assigns the
LUN values, or you can assign LUN values when you enable the Storage Partitioning premium feature. A
logical drive can have only one LUN and can be mapped to only one host or host group. Each host has
unique addressing capability. That is, when more than one host accesses a storage subsystem, each host
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IBM System Storage DS3000, DS4000, and DS5000: Command Line Interface and Script Commands Programming Guide