Silicon Graphics InfiniteStorage 4000 Series, Configuring And Maintaining

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50 Host Groups
Host Groups A host group is a topological element that you can define if you want to designate a
collection of hosts that will share access to the same volumes. A host group is a
logical entity. Host groups are identified by names or labels that users choose. The
host group name can be any combination of alphanumeric characters with a
maximum length of 30 characters.
Host Bus
Adapter Host
Ports A host bus adapter (HBA) provides the physical connection from the host to the
storage array. The host port is a physical connector on an HBA. The HBA is a circuit
board that is installed in the host. The HBA can have one or more host ports. Each
host port is identified by a unique, 16-byte World Wide Identifier (WWID). If the
HBA has more than one host port, each host port has a unique ID.
When you first turn on the power to a storage array, the storage management 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 array
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 volumes.
The maximum number of HBA host ports that you can logically define for your
storage array depends on the type of controller in the storage array. The following
table lists the maximum number of HBA host ports that you can define.
Table 10 Maximum Number of HBA Host Ports per Controller
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 volumes in a storage array. The hosts
identify the volumes that they want to access using the LUN values. When you create
a volume, the firmware assigns the LUN values, or you can assign LUN values when
you enable the SANshare Storage Partitioning premium feature. A volume 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
array, each host might use the same LUN to access different volumes. The LUNs
might be the same, but the volumes are different. If you are mapping to a host group,
the LUN that you specify must be available on every host in the host group.
Controller Models Maximum Number of Host Ports
1331, 1333, 1532, 1932 256
E2600 256
CDE3992 or CDE3994 256
CE4900 256
CE6998 512
CE7900 1024