Advanced Copy has three types of clone copies.
For details on the operation procedures, refer to "Perform the Advanced Copy" in the "ETERNUS SF Web Console Guide".
Clone copy (OPC)
This is a copy method to execute OPC of ETERNUS Disk storage system.
The clone copy (OPC) copies one volume. If copy source volume is accessed, it can copy the volume.
When the OPC command is invoked, ETERNUS Disk storage system creates a point in time snapshot of the source volume and then immediately returns a notification to the operator that the backup is complete, before any physical copying has even occurred. This allows for access to be returned to the transaction or source volume with little or no interruption while the copy is performed as a background process at the hardware level in ETERNUS Disk storage system.
The clone copy (OPC) is highly effective available for:
Generation backups where continuous uptime is critical such as internet business applications.
Restore from backups where OPC can be used regardless of the backup copy method and minimizing downtime.
Case where minimizing server I/O load is critical to overall business application performance.
The following diagram explains the process of clone copy (OPC).
Figure 4.3 Clone copy (OPC) diagram
Clone copy (QuickOPC)
This is a copy method to execute QuickOPC of ETERNUS Disk storage system.
When the QuickOPC command is invoked, it will determine if an initial copy exists, then will copy only updated blocks of data that have been tracked since the initial copy was created to the backup volume for that specific QuickOPC session.
If QuickOPC detects that an initial copy does not exist, it will create the initial copy using OPC. The differential copy method used in QuickOPC significantly reduces the time required for physical data copying in order to create a Point in Time snapshot while minimizing the I/O load on the storage system host server.
The clone copy (QuickOPC) is highly effective available for:
Backup to disk where uptime is critical.
Frequent restore point creation and frequent backups.
The following diagram represents the differential copy process used in QuickOPC copy after an initial copy has been created.
Figure 4.4 Clone copy (QuickOPC) diagram
Clone copy (EC)
This is a copy method to execute EC of ETERNUS Disk storage system.
The EC feature invokes a process of synchronization between source and destination volumes to create a synchronized copy of the source volume. The purpose of the synchronization is to reach and maintain a state of equivalence with the source volume in order to create a temporary copy or archival backup.
The source volume remains available and accessible as there is no need to stop or suspend access to the source volume while the copy is built using the synchronization process.
When a state of equivalence with the source volume has been attained, the destination volume continues to be maintained as an image of the source volume.
At any subsequent point while the source volume and the destination copy are in this state of equivalence, the destination copy can be split from the source, thus creating a backup with history or a replica copy as at that point in time.
The clone copy (EC) is highly effective available for:
Making backups much more quickly than with conventional backup processes, because backup data can be collected in parallel with ordinary transactions.
Reducing processing time and costs by means of distributed processing using copy data.
Figure 4.5 Clone copy (EC) diagram
