Remote Copy

Remote copy is a function that copies data between different storage systems in remote locations by using the "REC". REC is an enhancement of the EC mirror suspend method of the local copy function. Mirroring, snapshots, and backup between multiple storage systems can be performed by using an REC.

An REC can be used to protect data against disaster by duplicating the database and backing up data to a remote location.

The older models of the ETERNUS storage systems are connectable.

For details about interfaces between storage systems, refer to Remote Interfaces.

REC

REC is used to copy data among multiple storage systems using the EC copy method. REC is suitable for the following usages:

Performing system test data replication
Duplicating databases on multiple ETERNUS AF/DX storage systems
Backing up data to remote ETERNUS AF/DX storage systems

Figure: REC

The REC data transfer mode has two modes: the synchronous transfer mode and the asynchronous transfer mode. These modes can be selected according to whether importance is placed upon I/O response time or complete backup of the data is performed until the point when a disaster occurs.

Table: REC Data Transfer Mode
Data transfer mode	I/O response	Updated log status in the case of disaster
Synchronous transfer mode	Affected by transmission delay	Data is completely backed up until the point when a disaster occurs.
Asynchronous transfer mode	Not affected by transmission delay	Data is backed up until a few seconds before a disaster occurs.

For details about REC data transfer modes, refer to REC Data Transfer Mode Comparison.

For REC update information, refer to Update Information Management of REC.

For details about copy path errors while REC is operating, refer to Operations When All Copy Paths of REC Are Blocked.