Administrator Guide

The Default Group on the Host Mappings tab has a default host type. To change the host type, right-click on the host and select
Change Default Host Operating System from the pop-up menu. If you set the default host type to a host type that is restricted, the
maximum number of LUNs allowed in the Default Group for any host is restricted to the limit imposed by the restricted host type. If a
particular host with a nonrestricted host type becomes part of a specific storage partition, you are able to change the mapping to a higher
LUN.
Storage partitioning
A storage partition is a logical entity consisting of one or more virtual disks that can be accessed by a single host or shared among hosts
that are part of a host group. The first time you map a virtual disk to a specific host or host group, a storage partition is created.
Subsequent virtual disk mappings to that host or host group do not create another storage partition.
One storage partition is sufficient if:
• Only one attached host accesses all the virtual disks in the storage array
• All attached hosts share access to all the virtual disks in the storage array
When you choose this type of configuration, all the hosts must have the same operating system and special software (such as clustering
software) to manage virtual disk sharing and accessibility.
More than one storage partition is required if:
• Specific hosts must access specific virtual disks in the storage array
• Hosts with different operating systems are attached to the same storage array. In this case, a storage partition is created for each
host type
You can use the Storage Partitioning Wizard to define a single storage partition. The Storage Partitioning Wizard guides you through the
major steps required to specify which host groups, hosts, virtual disks, and associated logical unit numbers (LUNs) are to be included in
the storage partition.
Storage partitioning fails when:
• All mappings are defined
• You create a mapping for a host group that conflicts with an established mapping for a host in the host group
• You create a mapping for a host in a host group that conflicts with an established mapping for the host group
Storage partitioning is unavailable when:
• No valid host groups or hosts exist in the object tree on the Host Mappings tab
• No host ports are defined for the host being included in the storage partition
• 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 have read-only access until the virtual disk is promoted to a primary virtual disk, or the
replicate relationship is removed.
Storage partitioning topology is the collection of elements, such as Default Group, host groups, hosts, and host ports shown as nodes in
the object tree of the Host Mappings tab in the AMW. For more information, see Using The Host Mappings Tab.
If a storage partitioning topology is not defined, an informational dialog is displayed each time you select the Host Mappings tab. You
must define the storage partitioning topology before you define the actual storage partition.
Disk group and virtual disk expansion
Adding free capacity to a disk group is achieved by adding unconfigured capacity 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 disk expansion on a standard or snapshot repository virtual disk.
Disk group expansion
To add free capacity to a disk group:
1. In the AMW, select the Storage & Copy Services tab.
2. Select a disk group.
3. From the menu bar, select Storage > Disk Group > Add Physical Disks (Capacity). Alternatively, right-click on the disk group and
select Add Physical Disks (Capacity) from the pop-up menu.
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Disk groups, standard virtual disks, and thin virtual disks