asynchronous replication

(n.) A form of replication in which the Remote Mirror software confirms to the originating host that the primary I/O transaction is complete before updating the remote image. That is, completion of the I/O transaction is acknowledged to the host when the local write operation is finished and the remote write operation has been queued. Deferring the secondary copy removes long-distance propagation delays from the I/O response time.

configuration location

(n.) Network location where the Sun StorageTek Availability Suite software stores configuration information about all enabled volumes used by the software.

forward resynchronization

See Update synchronization.

full synchronization

(n.) A complete volume-to-volume copy operation, which is the most time-consuming of the synchronization operations. In most cases, a secondary volume is synchronized from its source primary volume. However, restoration of a failed primary disk might require reverse synchronization, using the surviving Remote Mirror as the source.

logging mode

(n.) Mode in which a bitmap tracks write operations to a disk rather than maintaining a running log of each I/O event. This method tracks disk updates that have not been remotely copied while the remote service is interrupted or impaired. The blocks that no longer match their remote sets are identified for each source volume. The software uses this log to re-establish a Remote Mirror through an optimized update synchronization rather than a complete volume-to-volume copy.

primary host,
primary volume

(n.) The system or volume on which the host application is principally dependent. For example, this is where the production database is being accessed. This data is replicated to the secondary host by the software. Also known as the "local host" or "local volume."


(n.) The process of maintaining the same data on both the primary and secondary volumes. Replication is driven by user-layer application write operations so replication is an ongoing process.

Reverse synchronization

(n.) An operation during which the primary volume is updated with the contents of the secondary volume.

Secondary host,
secondary volume

(n.) The remote counterpart of the primary host or primary volume, which data copies are written to and read from. Remote copies are transmitted without host intervention between peer servers. A server might act as primary storage for some volumes and secondary storage for others. Also known as "remote host" or "remote volume."


(n.) The process of establishing an identical copy of a source disk onto a target disk as a precondition for software mirroring.

Synchronous replication

(n.) Replication that is limited to short distances (tens of kilometers) because of the detrimental effect of propagation delay on I/O response times.

Update synchronization

(n.) Synchronization that copies only those disk blocks identified by logging, reducing the time required to restore remotely mirrored sets.

Volume set file

(n.) A text file containing information about specific volume sets. This text file is not the same as the configuration location, which contains information about all configured volume sets used by the Remote Mirror and Point-in-Time Copy software.