Configuration: Disk Groups and Virtual Disks 131Storage partitioning is unavailable when:• No valid host groups or hosts exist in the Topology pane on the Mappingstab.• No host ports are defined for the host being included in the storagepartition.• All mappings are defined.NOTE: You can include a secondary virtual disk in a storage partition.However, any hosts that are mapped to the secondary virtual disk has read-onlyaccess until the virtual disk is promoted to a primary virtual disk, or the mirrorrelationship is removed.Storage partitioning topology is the collection of elements, such as DefaultGroup, host groups, hosts, and host ports shown as nodes in the Topologypane of the Mappings tab in the AMW. For more information, see "Using theMappings Tab" on page 86.If a storage partitioning topology is not defined, an informational dialog isdisplayed each time you select the Mappings tab. You must define the storagepartitioning topology before you define the actual storage partition.Disk Group and Virtual Disk ExpansionAdding free capacity to a disk group is achieved by adding unconfiguredcapacity on the array to the disk group. Data is accessible on disk groups,virtual disks, and physical disks throughout the entire modification operation.The additional free capacity can then be used to perform a virtual diskexpansion on a standard or snapshot repository virtual disk.Disk Group ExpansionTo add free capacity to a disk group:1 In the AMW, select the Logical tab.2 Select a disk group.3 Select Disk Group Add Free Capacity (Physical Disks).The Add Free Capacity window is displayed. Based on the RAID level, andthe enclosure loss protection of the current disk group, a list of unassignedphysical disks is displayed.
