Learn About Defining Storage Partition Topology

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Storage partition topology is a collection of topological elements (Default Group, host groups, hosts, and host ports) shown as nodes in the Topology View of the Mappings View. You must define the various topological elements if you want to define specific logical drive-to-LUN mappings for host groups and/or hosts.

Note: Even if you are not planning to use Storage Partitioning, you can still define hosts and host ports connected to the storage subsystem and view the default logical drive-to-LUN mappings to determine which logical unit numbers are being used to access the logical drives in the storage subsystem.

Defining Storage Partition Topology

The following are the key topological elements that must be defined to create a storage partition:

Default Group

A Default Group is a standard node in the Topology View that designates all host groups, hosts, and host ports that: (1) do not have any specific logical drive-to-LUN mappings, and (2) share access to any logical drives that were automatically assigned default LUNs by the controller firmware during logical drive creation.

Host Group

A host group is an optional topological element that you define to designate a collection of hosts that will share access to the same logical drives. For more information, see Defining a Host Group.

Note: Define a host group ONLY if you have two or more hosts that will share access to the same logical drives.

Host

A host is a computer attached to the storage subsystem that accesses various logical drives on the storage subsystem through its host ports. You define a host as a separate entity or as part of a host group. Also, you can define specific logical drive-to-LUN mappings to an individual host and have the host be part of a host group that shares access to one or more logical drives. For more information, see Defining a Host.

Host Port

A host port is a physical connection on the host adapter that resides within a host. When the host adapter only has one physical connection (host port), the terms host port and host adapter are synonymous. Host ports are automatically detected by the storage management software. A host port is the actual physical connection that allows a host to gain access to the logical drives in a storage subsystem. Therefore, if you want to define specific logical drive-to-LUN mappings for a particular host and create storage partitions, you must define its associated host ports. Initially, all detected host ports belong to the Default Group and have access to any logical drives that were automatically assigned default LUNs by the controller firmware during logical drive creation. For more information, see Defining a Host Port.

Any host port in the Default Group can automatically access the following logical drives:

  • Logical Drive's that, when created, were given default logical drive-to-LUN mappings .
  • Any logical drives created using previous versions of this storage management software. Such logical drives are automatically given default logical drive-to-LUN mappings. If desired, you can change these mappings by selecting the particular mapping and selecting the Mappings >> Change >> Mapping pull-down menu option. For more information, see Changing a Logical Drive-to-LUN Mapping.
  • A factory-configured Access Logical Drive used for communication between the storage management software an a host-agent managed storage subsystem. An Access Logical Drive mapping is not needed for directly managed storage subsystems and may be deleted. For more information, see Deleting a Host Port, Host, Host Group, or Logical Drive Mapping.

Example

In the following example, the logical drives in Storage Subsystem Midwest have not been given specific logical drive-to-LUN mappings; the controller firmware has automatically assigned them. Therefore, any host and associated host ports from the Default Group can request data from these logical drives.

Reconfiguring Storage Partition Topology

A storage partitions topology is reconfigurable. You can:

Related Topics

Learn About Creating Storage Partitions

Learn About Using the Mappings View

Using the Storage Partitioning Wizard