Storage partitioning – Dell PowerVault MD3820f User Manual

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Group for any host is restricted to the limit imposed by the restricted host type. If a particular host with a
non-restricted 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 of the virtual disks in the storage array
• All attached hosts share access to all of the virtual disks in the storage array

When you choose this type of configuration, all of 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 has read-only access until the virtual disk is promoted

to a primary virtual disk, or the mirror 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.

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