Managing lun paths, About lun path management – HP XP P9000 Command View Advanced Edition Software Licenses User Manual
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Managing LUN Paths
This module describes path management; how to specify LUN paths, edit host mode and host mode
options, and how to specify LUN paths after replacing or exchanging a host bus adapter.
About LUN path management
When you allocate a volume to a host, HP StorageWorks P9000 Command View Advanced Edition
Suite allows you to assign or edit LUN paths between one or more volumes and one or more hosts.
LUN paths provide volume access for the host by pairing storage ports and host ports. For example,
one or more storage ports can be mapped to one or more host ports.
After volumes have been allocated to a host, you can edit existing LUN path information to add new
paths or delete existing paths from a list of allocated volumes in the storage systems tree, hosts tree,
logical groups tree, and from a list of volumes returned from a search.
To set a new LUN path between a specific volume and a host , perform the allocate volume operation,
and to delete all the LUN path settings between a specific volume and a host , perform the unallocate
volume operation. In contrast, in LUN path editing, you can change the number of LUN paths and
the connection-destination ports according to operations. In particular, edit LUN paths to achieve the
following:
•
Improvement of I/O performance
If the usage frequency of an application increases, you can add LUN paths to increase the data
transmission speed and improve the I/O performance. If the usage frequency decreases, you can
delete the LUN paths.
•
Enhancements to system redundancy
To prepare for an error in storage systems or host ports, you can enhance the system redundancy
by configuring multiple LUN paths, with each using a different port.
•
Response to failures
When a port is disabled because of an error, you can configure LUN paths that temporarily use
alternate ports to continue system operation.
Because allocated volumes belong to a specific host group, the same target host port is set for all
volumes in any given host group. Therefore, when adding or deleting a host port for one or more
volumes, you must select all of the volumes that belong to that host group to maintain consistent LUN
path assignments for all volumes.
You can change host modes and host mode options depending on the situation, for example when
an application is added to the host and the operating system is upgraded.
You can add or exchange HBAs to improve performance and throughput requirements. To edit LUN
paths when replacing a failed HBA or performing a planned HBA replacement, use any of the following
options, depending on your task purpose:
•
Add HBA
•
Exchange HBA
•
Remove HBA
You can use the LUN paths that were set for the old HBA for the new HBA, and delete LUN paths set
for an HBA that is no longer necessary. You can also edit LUN paths for multiple HBAs collectively.
Related topics
User Guide
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