3.7.0 HP StorageWorks HP Scalable NAS File Serving Software administration guide - HP Scalable NAS 3.7 for Linux (AG513-96002, October 2009)

7 Configure dynamic volumes
HP Scalable NAS includes a Cluster Volume Manager that you can use to create,
extend, recreate, or delete dynamic volumes. Dynamic volumes allow large filesystems
to span multiple disks, LUNs, or storage arrays.
Dynamic volumes can be deported from the cluster and later imported back into the
original cluster or into another cluster.
Overview
Basic and dynamic volumes
Volumes are used to store PSFS filesystems. There are two types of volumes: dynamic
and basic.
Dynamic volumes are created by the Cluster Volume Manager. They can include one
or more disks, disk partitions, or LUNs that have been imported into the cluster. These
entities are called subdevices. A single PSFS filesystem can be placed on each
dynamic volume. Additional subdevices can be added to a dynamic volume as
necessary, and the filesystem on the volume can also be extended.
A basic volume consists of a single disk, disk partition, or LUN that has been imported
into the cluster. A PSFS filesystem is then created directly on the disk, partition, or
LUN. Basic volumes can be converted to dynamic volumes.
Types of dynamic volumes
HP Scalable NAS supports two types of volumes: striped and concatenated. The
volume type determines how data is written to the volume.
• Striping. When a dynamic volume is created with striping enabled, a specific
amount of data (called the stripe size) is written to each subdevice in turn. For
example, a dynamic volume could include three subdevices and a stripe size of
64 KB. That amount of data will be written to the first subdevice, then to the
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