Key terms

access attributes

Security function used to restrict the access to a logical volume. Using Data Retention Utility, you can assign an access attribute to each volume: read only, read/write, or protect.

capacity expansion

The data compression services provided by the FMC drives, called accelerated compression.

capacity saving

The data deduplication and data compression functions provided by the storage system controllers.

CV

Custom-size volume. CVs are created by dividing a fixed-size volume (FV) into user-defined sizes.

deduplication system data volume

The volume used to manage data deduplication in a pool. The deduplication system data volume (also called DSD volume) is created when you enable deduplication on a pool.

DP pool

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

DP-VOL

A virtual volume (V-VOL) used for Dynamic Provisioning.

expiration lock

Security option used to allow or prevent changing of the Data Retention Utility access attribute on a volume.

FMC (flash module compression)

A large-capacity flash module drive (FMD) that supports the accelerated compression functionality. A dedicated drive box is required for the FMC drives. The FMC drives and the dedicated FMC drive box are collectively referred to as Accelerated Flash DC2 (HAF DC2).

FV

Fixed-sized volume.

With the exception of OPEN-V, an FV is a logical volume of a specific device emulation type (for example, OPEN-3) that constitutes a parity group immediately after installation. The FV size varies according to the emulation type.

meta_resource

A resource group to 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 allocated from a DP pool to store data written to a DP-VOL.

pool

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

pool threshold

In Dynamic Provisioning, the proportion (%) of used capacity of the pool to the total pool capacity. Each pool has its own pool threshold values for warning and depletion.

pool volume (pool-VOL)

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

resource group

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

subscription limit

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

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 is equal to the DP pool 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.