The following functions are available for local replication with clones:
QuickOPC function
EC (Equivalent Copy) function
Coexistence of QuickOPC and EC
On ETERNUS DX/AF and for new applications, the usage of the more flexible and strategic QuickOPC is recommended, see section “Clone units with QuickOPC, EC” in "Clone unit with complete copy of the original data".
Clones mirrored with QuickOPC or EC can exist in parallel on an ETERNUS DX/AF storage system. The parallel mirroring of single volumes is not possible. The parallel usage of QuickOPC and EC is only recommended for a transitional phase in which some pubsets are mirrored with QuickOPC and others with EC.
You can specify which clone function to use for the START-CLONE-SESSION command centrally and globally in the SHC-OSD parameter file and selectively in the command itself with the CLONE-TYPE parameter. An explicit specification in the command overweighs the settings in the SHC-OSD parameter file.
Overview on local replication
The commands for the QuickOPC and EC Clone functions control replication functions which assign one or more clone units to an original unit and manage the clone pairs (clone sessions) created. The SHOW commands display their current processing status, the status of the clone sessions and the configuration.
The functions execute in a similar manner and are controlled in BS2000 by SHC-OSD with the same commands. The functions are consequently (to some degree) presented in parallel in this chapter:
Section |
Commands for QuickOPC and EC
Command | Function |
Activates a clone pair (EC) | |
Re-creating a clone pair | |
Reconstructs an original from a clone unit | |
Displays the status of clone pairs | |
Displays the configuration | |
Displays device configuration | |
Creates a clone pair | |
Cancels a clone pair | |
Swaps original and clone attributes of a clone pair (with EC) |