Security function that restricts 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.
adaptive data reduction (ADR)
Reduces the amount of data used in a pool. The Hitachi storage systems deliver controller-based deduplication and compression to provide system-level storage efficiency savings. In addition, SVOS manages the ADR services used based on configuration.
The term "Adaptive Data Reduction" (capitalized) is the name of the software license on the storage system.
ALU/SLU
The storage systems can be integrated with a VMware® ESXi host or VMware® vCenter Server by Storage Provider for VMware® vCenter, which provides support for vSphere APIs for Storage Awareness (VASA). Snapshot and replication functions are used in storage systems that are configured with Administrative Logical Units (ALUs) and Subsidiary Logical Units (SLUs).
capacity saving
The capacity saving function includes data deduplication and data compression. Capacity saving enables you to reduce your bitcost for the stored data by deduplicating and compressing the data. These deduplication and compression functions are performed by the controllers of the storage system.
The term "dedupe and compression" is the name of the software license on the storage system for capacity saving.
child
In Thin Image Advanced, a pair or a volume that shares metadata with a parent.
If no volumes with the vClone attribute exist in a family, the child contains a pair or a volume that belongs to the same snapshot tree as a root volume.
If a volume with the vClone attribute exists in the family, the child contains a pair or a volume that belongs to the same snapshot tree as a volume with the vClone Parent attribute, a volume with the vClone attribute in the same family, and a pair or a volume that belongs to the same snapshot tree as the volume with the vClone attribute in the same family.
compression accelerator
Hardware-based feature that performs data compression instead of the controllers performing the data compression. The data-size saving rate due to data compression is also improved.
compression accelerator module
Hardware component that includes the compression accelerator and a fan.
copy threshold option
Prevents the write response performance for a V-VOL with capacity saving enabled from being degraded due to overload by the copy processing of a replication program product that runs on the background.
data retention
After provisioning your system, you can assign access attributes to open-system volumes to protect the volumes against read, write, and copy operations and to prevent users from configuring LU paths and command devices. Data Retention Utility software is required to assign access attributes to volumes.
deduplication system data volumes
The volumes that manage data deduplication in a pool. Deduplication system data volumes (also called DSD volumes) are created when you enable deduplication.
DP pools
A group of thin-provisioned volumes (V-VOLs) that are used as a single shared pool of storage.
DP-VOL
A virtual volume (V-VOL) that is used for following functions:
Journal volume of Universal Replicator
Virtual volume with DDM attribute
Deduplication system data volume (created automatically)
DRS-VOL
A data reduction shared volume (DRS-VOL) is a virtual volume (V-VOL) that is created by using capacity saving of Adaptive Data Reduction.
DRS-VOL with capacity saving enabled
A V-VOL with the capacity saving function of Adaptive Data Reduction enabled and the capacity saving setting (deduplication or deduplication and compression) enabled.
DRS-VOL with capacity saving disabled
A V-VOL with the capacity saving function of Adaptive Data Reduction enabled and the capacity saving setting (deduplication or deduplication and compression) disabled.
Dynamic Provisioning
By using virtual volumes, Dynamic Provisioning allows you to allocate capacity to a virtual host (server) in excess of the available physical capacity. The data of the virtual volume is stored in the storage pool. Each time you increase capacity, you need to prepare only a minimum number of data drives and do not need to stop the system.
external volume
A volume that maps a volume on the external storage system to the local storage system by using Universal Volume Manager.
family
In Thin Image Advanced, a group that contains a parent (a volume from which metadata is shared) and a child (a pair or a volume that shares metadata with the parent) sharing metadata.
host group
A host group contains all the hosts connected to a storage system that have a specific OS and that are connected to the same port.
host mode
The host mode tells the storage system the data format of the host with which it communicates. You set host modes only for Fibre Channel and iSCSI targets.
host mode option
Host mode options enable you to tailor your storage system to your unique operating requirements.
NVMe over Fibre Channel (NVMe-oF)
Feature that provides NVMe protocol over front-end FC connections.
page
In Dynamic Provisioning, a page is 42 MB of continuous storage allocated from a DP pool to store data written to a DP.
parent
In Thin Image Advanced, a volume from which metadata is shared. If no volumes with the vClone attribute exsit in a family, the parent contains a root volume. If a volume with the vClone attribute exists in the family, the parent contains a volume with the vClone Parent attribute.
parity group
VSP One Block supports RAID 1, RAID 5, and RAID 6 parity groups.
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 Advanced snapshot data.
Quality of Service
QoS is a network technology that manages traffic and prioritizes applications to ensure performance.
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.
saving effect
When capacity saving is used, the saving ratio is calculated to include user data, metadata, and garbage data (generated by the system).
server object
A set of host groups that are managed together. A server object includes information about each host group's host bus adapters, enabling you to manage the set of host groups as a single object.
snapshot data
In Thin Image Advanced, a duplicate of data at a specific point in time.
software saving
When capacity saving is used, the software saving ratio is calculated with user data, metadata, and garbage data (generated by the system).
spare area
In parity groups, the drives have spare area to use in case of a drive failure, and dedicated spare drives are not required.
subscription limit
In a thin-provisioned storage system, the proportion (%) of total V-VOL capacity associated with the pool versus the total capacity of the DP pool. You can set the percentage of V-VOL capacity that can be created to the total capacity of the pool. This can help prevent V-VOL blocking caused by a full pool. For example, when the subscription limit is set to 100%, the total DP capacity is equal to the DP pool capacity.
thin provisioning
Thin provisioning technology allows you to allocate virtual storage capacity based on anticipated future capacity needs, using virtual volumes instead of physical drives. The Hitachi version of thin provisioning is called Dynamic Provisioning.
Total Efficiency Ratio
The total saving effect achieved by capacity saving (controller-based compression and deduplication), Dynamic Provisioning, and snapshot. System data (metadata and garbage data for the capacity saving function, Thin Image Advanced metadata) is not included in the Total Efficiency Ratio.
virtual storage machine
A container that is used to manage virtualized storage system resources. When you use global storage a virtualization function (global-active device), you create a virtual storage machine within a physical storage system to enable the server to recognize two storage systems as one virtual storage system. You can create multiple virtual storage machines within a physical storage system.
virtual volume (V-VOL)
A volume that does not have physical storage space. A V-VOL is created from a Dynamic Provisioning pool. A virtual volume is displayed as a volume on VSP One Block Administrator. V-VOLs used for DP are different from V-VOLs used for Thin Image Advanced (called DRS-VOLs). DRD-VOLs are also a type of V-VOL.
volume with the vClone Parent attribute
In Thin Image Advanced, a volume from which the metadata is shared if a volume with the vClone attribute exists in a family.
volume with the vClone attribute
In Thin Image Advanced, a volume that stores snapshot data obtained by creating a virtual clone.
V-VOL with capacity saving disabled
A V-VOL with the capacity saving function of adaptive data reduction disabled (such as a DP-VOL with direct data mapping enabled).