Allow Large Chunk Mode

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Allow Large Chunk Mode

Allow Large Chunks Mode:
 
|--+- -BC 1-+---------------------------------------------------|
   '- -BC 2-'

Element	Purpose	Key Considerations
-BC 1	Enables support of large chunks, large offsets that are greater than 2 GB, and allows more than 2047 chunks per dbspace.	Additional Information: This option allows large chunks to be created. Reversion is possible if there are no large chunk features in the server, the root chunk or none added. Dbspaces and blobspaces without chunks greater than 2 GB remain in the old version. After a chunk larger than 2 GB is added to a dbspace or blobspace then all chunks added or altered in that dbspace or blobspace are in the new format. References: See your IBM Informix Administrator's Guide.
-BC 2	Allows large-chunk-only mode for all dbspaces.	Additional Information: Reversion is not possible. Enables the 9.4 large chunk feature for all dbspaces and blobspaces, Any chunk or offset added or modified has the new format. Existing chunks that you do not alter remain in the old format. References: See your IBM Informix Administrator's Guide

The onmode -BC (backward-compatible) commands are useful if you have converted from Dynamic Server 9.40 (small chunk mode) to Dynamic Server 10.0. When Dynamic Server 10.0 is first initialized (with the oninit -iyv command), by default it comes online with large chunk mode already fully enabled. Reversion is not possible. In the case of a newly initialized instance of Dynamic Server 10.0, the onmode -BC commands will return an error.

Note:

After executing the onmode -BC command, perform a complete system level-0 backup.