Automated Storage Tiering
Performance-dependent use of the capacity of storage systems by automatically controlled data migration. -> Flexible Tier Pool. -> Flexible Tier Volume. -> tiering policies.
cascaded remote copy
-> remote copy configuration
channel adapter (CA)
-> channel adapter
channel adapter
The channel adapters process input/output requests from the server end and control access to the storage system cache.
clone pair, clone pubset, clone session, clone unit
A clone unit is the copy of an original unit at a particular time (“Point-in-Time copy”). The local replication functions of the storage systems create this copy optionally as a complete copy or as a “snapshot”.
After they have been activated, the original unit and clone unit are split; applications can access both.
The original unit and clone unit together form a clone pair and are managed in what is known as a clone session.
If clone units exist for all original units of a pubset, these clone units together form the clone pubset.
concurrent remote copy
-> remote copy configuration
concurrent target unit
-> target unit in a concurrent -> remote copy configuration
data striping
Distribution of the individual data blocks of a file across the access systems.
disaster tolerant disk system (DTDS)
The highest level of security in the new system of classification of the RAB (Raid Advisory Board). This level is attained by storage systems that are protected against data loss and failure over a wide area by means of redundant, geographically distant data recording.
Equivalent Copy (EC)
Replication function for ETERNUS DX/AF which offers the clone functionality.
ETERNUS DX/AF
ETERNUS DX/AF systems are high-availability storage systems of Fujitsu.
failback
Failback denotes a return to recovered resources after a failover.
In this manual this especially refers to:
the return of applications from target units to source units in a remote copy configuration
the return to the primary storage system in a Storage Cluster
failover
In general, failover is the switching procedure from failed resources to redundant identical resources.
In this manual this especially refers to:
the activation of the target units in a remote copy configuration
the switching to the secondary storage system in a Storage Cluster
flexible tier pool (flex pool for short)
Predefined pool for managing the -> flexible tier volumes.
flexible tier subpool (flex subpool for short)
Performance-dependent pool containing -> flexible tier volumes in the -> flexible tier pool.
flexible tier volume (flex volume for short)
Generated volumes in the -> flexible tier subpool.
local storage system
The local storage system is located in the local Data Center and generally contains the source units. All I/Os are written to the source unit first.
local system
The local system is located in the local Data Center. The original processing takes place on the local system. In normal operation it sends the I/Os to the local storage system.
POSIX semaphores
Variables which control access to a shared resource.
QuickOPC
Replication function for ETERNUS DX/AF which offers the clone functionality.
RAID0
RAID0 implements the distribution of the individual data blocks of a file (“data striping”) without data backup.
RAID1
RAID1 fully duplicates data on double the number of disks.
RAID5
RAID5 implements joint parity checking for several disk drives with distribution of the individual data blocks of a file over the disk drives (no -> data striping).
RAID5 can be configured as 3+1 or 7+1.
RAID6
RAID6 implements joint parity checking for several disk drives with distribution of the individual data blocks of a file over the disk drives. The data is then also protected when a second drive fails during a “rebuild process”. RAID6 can be configured as 6+2 or 14+2.
RAID10
RAID10 implements the distribution of the individual data blocks of a file (-> data striping) and at the same time fully duplicates the data on double the number of disks (RAID1 and RAID0).
Redundant Array of Independent Disks (RAID)
RAID refers to a technological concept for improving data availability. RAID levels RAID0 through RAID10 exist.
Remote Equivalent Copy (REC)
Function of ETERNUS DX/AF for creating (additional) copies of application data of a local storage system in other, geographically distant storage systems.
remote copy configuration
Configuration when remote replication is used: The data of a local storage system is mirrored to one or more remote storage systems. There are the following configuration variants:
Single remote copy configuration with
->remote copy pairsConcurrent remote copy configuration with
->remote copy pairs which operate simultaneously (concurrently)Switched remote copy configuration (SAN connection)
remote copy pair
A remote copy pair consists of a source unit (original, local storage system) and a target unit (data copy, remote storage system) that are connected to each other by means of a remote link.
remote storage system
The remote storage system is located in the remote Data Center and generally contains the target units. If the entire local Data Center fails (local system and local storage system), the target units are released for use by the standby system.
save device
Save devices save all original data which was modified on the original unit (and also on the snap unit) in the course of a snap session
Save Pool / Snap Data Pool (SDP)
-> snap pair
SMI-S
Storage Management Initiative Specification, the standard which is defined and supported by the SNIA (Storage Networking Industry Association) for non-proprietary, uniform management of storage systems.
SnapOPC+
Name of the snap function for ETERNUS DX/AF with the option of creating and operating multiple snap sessions for one original unit.
Snap Data Volume (SDV), Snap Data Pool Volume (SDPV), Snap Data Pool Element (SDPE)
SnapOPC+ uses specially configured devices in the storage system, which are known as Snap Data Volumes (SDVs), as snap units. If the capacity of the SDV has been exhausted, it is provided with further capacity from a central pool (Snap Data Pool, SDP) of the storage system by one or more Snap Data Pool Elements (SDPEs) being made available.
snap pair, snap pubset, snap session, snap unit
A snap unit is the copy of an original unit at a particular time (“Point-in-Time copy”). The local replication functions of the storage systems create this copy
as a “snapshot” in accordance with the “Copy-On-First-Write strategy“: Only if data is modified is the original data concerned written beforehand into a snap save area (Save Pool / Snap Data Pool) of the storage system. The snap unit contains the references to the original data. In the case of unmodified data the references point to the original unit, in the case of modified data to the snap storage area.
After they have been activated, the original unit and snap unit are split; applications can access both.
The original unit and snap unit together form a snap pair and are managed in what is known as a snap session.
If snap units exist for all units of a pubset, these snap units together form the snap pubset.
source path
Input/output path from the local system to the -> source unit
source unit
The source unit is generally located on the local storage system. All I/Os are written to the source unit first.
standby system
The standby system is located in the remote Data Center. It takes over processing if the local system fails and normally uses the target path to the remote storage system.
Storage Cluster
The “Storage Cluster Option (SCO)” function links two ETERNUS DX/AF storage systems to a failsafe storage system, so called “Storage Cluster”.
switched remote copy
-> remote copy configuration
target path
Input/output path from the standby system to the -> target unit
target unit
The target unit is usually located on the remote storage system. The target unit is a copy of the source unit and is synchronized with it. In the event of a failure, the target unit receives I/Os via the target path.
thin device
Thin volume with a large capacity. Virtual volumes occupy physical storage from a jointly used storage pool as required. -> thin pool
thin pool
Predefined pool for managing the -> thin devices.
Thinpoolavoid file
Optional file thinpoolavoid in POSIX directory var/shcosd/config in which a list of thin pools can be specified which are not to be monitored by SHC-OSD when THIN-POOL-MONITORING=BY-AVOID-FILE or FLEX-POOL-MONITORING=BY-AVOID-FILE is specified in the SHC-OSD parameter file.
thin provisioning
Efficient use of the capacity of storage systems by virtual volumes with a large capacity. -> Thin Provisioned Volume (TPV).
Thin Provisioned Pool (TPP, thin pool for short)
Predefined pool of physical disks to provide the physical storage space for -> Thin Provisioned Volumes (TPVs).
Thin Provisioned Volume (TPV)
Virtual volume with a large capacity. Virtual volumes
occupy physical storage from a jointly used storage pool as required. -> thin pool (TPP).
tiering policies
Rules for -> Automated Storage Tiering. -> Flexible Tier Pool.
virtual device
The virtual device of the storage system is the -> snap unit, which can be accessed from the server.