access attributes

Security function used to control the access to a logical volume. Access attributes are assigned to each volume: read only, read/write, and protect.

CV (variable volume)

Customized Volume. A fixed volume that is divided into arbitrary sizes.

DP pool

A group of DP-VOL. The DP pool consists of one or more pool-VOLs.

DP-VOL

Dynamic Provisioning virtual volume.

expiration lock

Security option used to allow or not allow changing of the access attribute on a volume.

FV

Abbreviation for fixed-sized volume.

meta_resource

A resource group in which additional resources (other than external volumes) and the resources existing before installing Resource Partition Manager belong.

page

In Dynamic Provisioning, a page is 42 MB of continuous storage in a DP-VOL that belongs to a DP-pool.

pool

A set of volumes that are reserved for storing Dynamic Provisioning or Thin Image write data.

pool threshold

In a thin provisioned storage system, the proportion (%) of used pool capacity to the total pool capacity. Each pool has its own pool threshold values for warning and depletion.

pool-VOL, pool volume

A volume that is reserved for storing snapshot data for Thin Image operations or write data for Dynamic Provisioning.

resource group

A group that is assigned one or more resources of the storage system. The resources that can be assigned to the resource group are LDEV IDs, parity groups, external volumes, ports, host group IDs, and iSCSI targets.

subscription threshold

In a thin provisioned storage system, the proportion (%) of total DP-VOL capacity associated with the pool versus the total capacity.

You can set the percentage of DP-VOL capacity that can be created to the total capacity of the pool. This can help prevent DP-VOL blocking caused by a full pool.

For example, when the subscription limit is set to 100%, the total DP-VOL capacity that can be created is obtained using this formula:

total DP-VOL capacity <= pool capacity × 100%

Using this setting protects the pool when doing the following:

• Shrinking a pool

• Creating DP-VOL

• Increasing DP-VOL capacity

tier boundary

The value of the reached maximum I/O counts that each tier can process.

tier relocation

A combination of determining the appropriate storage tier and migrating the pages to the appropriate tier.

tiered storage

A storage hierarchy of layered structures of data drives consisting of different performance levels, or tiers, that match data access requirements with the appropriate performance tiers.