About allocating volumes – HP XP Array Manager Software User Manual

Page 138

About allocating volumes

Volume allocation makes storage capacity available to host applications or clustered hosts and
applications. Hosts must already be registered before volume allocation.

Depending on your registered storage systems, volumes can be allocated using basic volumes, pool
volumes, or volumes from a tier. Basic volumes are volumes from a parity group. Any storage system
can provide basic volumes. Allocating THP/Smart pool volumes involves grouping resources on
storage systems that support this feature. THP/Smart pools must exist prior to volume allocation from
a THP/Smart pool. To allocate volumes from a tier, a Tiered Storage Manager license is required,
and tier policies must be established for storage systems that support tier policy configuration.

The following rules and behaviors apply when allocating volumes:

•

Settings that are assigned when allocating volumes to a host become the default settings for the
next time you allocate a volume to the same host. You can change these settings during volume
allocation.

•

If a variety of volumes with different characteristics have been allocated to a host, when you allocate
a new volume, you can select an existing volume to set the volume allocation criteria.

•

When allocating a volume, if no volumes match the specified requirements, new volumes are
created from unused capacity and allocated to the host. When a basic volume is created, the
volume is also formatted at the same time.

•

You can use keyword or criteria-based searches to find existing unallocated volumes that meet
your requirements.

•

When you allocate volumes to a host, LUN paths are assigned automatically.
LUN paths are storage port to host port mappings that provide host access to volumes. The host
port is a host bus adapter (HBA). WWN nicknames can be displayed to confirm target HBAs for
a host while editing LUN paths during, or after, volume allocation.

•

Volumes can be allocated on ports where LUN security is not enabled. All hosts with access to the
port can access the volume.

•

Volume allocation to a cluster should be done by using logical groups. Using logical groups ensures
that the same volumes are allocated to all hosts in the cluster.

•

Volume allocation is not complete until you approve the volume allocation plan and submit the
volume allocation task.

•

When volumes are allocated to a host OS, you must create a file system on them and mount them,
before they can be used by host applications.

NOTE:

Before allocating volumes, review the available volume allocation methods. Understanding the available
starting points for volume allocation will enable you to perform volume allocation in a way that best
suits your requirements, and will help you understand the Allocate Volumes dialog box and the
Define Clustered-Host Storage dialog box.